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Trygve Helgaker - Publications

Affiliations: 
Department of Chemistry University of Oslo, Norway, Oslo, Oslo, Norway 
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309 high-probability publications. We are testing a new system for linking publications to authors. You can help! If you notice any inaccuracies, please sign in and mark papers as correct or incorrect matches. If you identify any major omissions or other inaccuracies in the publication list, please let us know.

Year Citation  Score
2023 Culpitt T, Peters LDM, Tellgren EI, Helgaker T. Time-dependent nuclear-electronic orbital Hartree-Fock theory in a strong uniform magnetic field. The Journal of Chemical Physics. 158: 114115. PMID 36948801 DOI: 10.1063/5.0139675  0.302
2022 Teale AM, Helgaker T, Savin A, Adamo C, Aradi B, Arbuznikov AV, Ayers PW, Baerends EJ, Barone V, Calaminici P, Cancès E, Carter EA, Chattaraj PK, Chermette H, Ciofini I, et al. DFT exchange: sharing perspectives on the workhorse of quantum chemistry and materials science. Physical Chemistry Chemical Physics : Pccp. PMID 36269074 DOI: 10.1039/d2cp02827a  0.745
2022 Peters LDM, Culpitt T, Tellgren EI, Helgaker T. Magnetic-translational sum rule and approximate models of the molecular Berry curvature. The Journal of Chemical Physics. 157: 134108. PMID 36208997 DOI: 10.1063/5.0112943  0.404
2022 Monzel L, Pausch A, Peters LDM, Tellgren EI, Helgaker T, Klopper W. Molecular dynamics of linear molecules in strong magnetic fields. The Journal of Chemical Physics. 157: 054106. PMID 35933207 DOI: 10.1063/5.0097800  0.358
2022 Pemberton MJ, Irons TJP, Helgaker T, Teale AM. Revealing the exotic structure of molecules in strong magnetic fields. The Journal of Chemical Physics. 156: 204113. PMID 35649858 DOI: 10.1063/5.0092520  0.321
2022 Culpitt T, Peters LDM, Tellgren EI, Helgaker T. Analytic calculation of the Berry curvature and diagonal Born-Oppenheimer correction for molecular systems in uniform magnetic fields. The Journal of Chemical Physics. 156: 044121. PMID 35105065 DOI: 10.1063/5.0079304  0.319
2021 Culpitt T, Peters LDM, Tellgren EI, Helgaker T. Ab initio molecular dynamics with screened Lorentz forces. I. Calculation and atomic charge interpretation of Berry curvature. The Journal of Chemical Physics. 155: 024104. PMID 34266267 DOI: 10.1063/5.0055388  0.375
2020 Ryley MS, Withnall M, Irons TJP, Helgaker T, Teale AM. Robust All-Electron Optimization in Orbital-Free Density-Functional Theory Using the Trust-Region Image Method. The Journal of Physical Chemistry. A. PMID 33356245 DOI: 10.1021/acs.jpca.0c09502  0.352
2020 Brandenburg JG, Burke K, Fromager E, Gatti M, Giarrusso S, Gidopoulos NI, Gori-Giorgi P, Gowland D, Helgaker T, Hodgson MJP, Lacombe L, Levi G, Loos PF, Maitra NT, Maurina Morais E, et al. New approaches to study excited states in density functional theory: general discussion. Faraday Discussions. PMID 33245076 DOI: 10.1039/d0fd90026e  0.673
2020 Fromager E, Gidopoulos N, Gori-Giorgi P, Helgaker T, Loos PF, Malcomson T, Pernal K, Savin A, Truhlar DG, Wibowo M, Yang W. Strong correlation in density functional theory: general discussion. Faraday Discussions. PMID 33241821 DOI: 10.1039/d0fd90025g  0.692
2020 Brandenburg JG, Burke K, Cancio A, Erhard J, Fromager E, Ghosal A, Gidopoulos N, Gori-Giorgi P, Helgaker T, Hourahine B, Jacob CR, Kooi D, Maitra N, Mulay MR, Pernal K, et al. New density-functional approximations and beyond: general discussion. Faraday Discussions. PMID 33232402 DOI: 10.1039/d0fd90023k  0.737
2020 Castro AC, Balcells D, Repisky M, Helgaker T, Cascella M. First-Principles Calculation of H NMR Chemical Shifts of Complex Metal Polyhydrides: The Essential Inclusion of Relativity and Dynamics. Inorganic Chemistry. PMID 33226791 DOI: 10.1021/acs.inorgchem.0c02753  0.652
2020 Olsen JMH, Reine S, Vahtras O, Kjellgren E, Reinholdt P, Hjorth Dundas KO, Li X, Cukras J, Ringholm M, Hedegård ED, Di Remigio R, List NH, Faber R, Cabral Tenorio BN, Bast R, ... ... Helgaker T, et al. Dalton Project: A Python platform for molecular- and electronic-structure simulations of complex systems. The Journal of Chemical Physics. 152: 214115. PMID 32505165 DOI: 10.1063/1.5144298  0.761
2020 Irons TJP, Spence L, David G, Speake B, Helgaker T, Teale AM. Analysing Magnetically Induced Currents in Molecular Systems Using Current-Density-Functional Theory. The Journal of Physical Chemistry. A. PMID 31986039 DOI: 10.1021/Acs.Jpca.9B10833  0.371
2020 Pasteka LF, Helgaker T, Saue T, Sundholm D, Werner H, Hasanbulli M, Major J, Schwerdtfeger P. Atoms and molecules in soft confinement potentials Molecular Physics. 1730989. DOI: 10.1080/00268976.2020.1730989  0.304
2019 Holzer C, Teale AM, Hampe F, Stopkowicz S, Helgaker T, Klopper W. GW quasiparticle energies of atoms in strong magnetic fields. The Journal of Chemical Physics. 150: 214112. PMID 31176321 DOI: 10.1063/1.5093396  0.782
2019 Laestadius A, Tellgren EI, Penz M, Ruggenthaler M, Kvaal S, Helgaker T. Kohn-Sham theory with paramagnetic currents: compatibility and functional differentiability. Journal of Chemical Theory and Computation. PMID 31063689 DOI: 10.1021/Acs.Jctc.9B00141  0.408
2019 Castro AC, Fliegl H, Cascella M, Helgaker T, Repisky M, Komorovsky S, Medrano MÁ, Quiroga AG, Swart M. Four-component relativistic P NMR calculations for trans-platinum(ii) complexes: importance of the solvent and dynamics in spectral simulations. Dalton Transactions (Cambridge, England : 2003). PMID 30916692 DOI: 10.1039/C9Dt00570F  0.796
2019 Holzer C, Teale AM, Hampe F, Stopkowicz S, Helgaker T, Klopper W. Erratum: “GW quasiparticle energies of atoms in strong magnetic fields” [J. Chem. Phys. 150, 214112 (2019)] The Journal of Chemical Physics. 151: 069902. DOI: 10.1063/1.5120100  0.354
2018 Adamowicz L, Stanke M, Tellgren E, Helgaker T. A computational quantum-mechanical model of a molecular magnetic trap. The Journal of Chemical Physics. 149: 244112. PMID 30599715 DOI: 10.1063/1.5055767  0.371
2018 Laestadius A, Penz M, Tellgren EI, Ruggenthaler M, Kvaal S, Helgaker T. Generalized Kohn-Sham iteration on Banach spaces. The Journal of Chemical Physics. 149: 164103. PMID 30384752 DOI: 10.1063/1.5037790  0.346
2018 Holzer C, Gui X, Harding ME, Kresse G, Helgaker T, Klopper W. Bethe-Salpeter correlation energies of atoms and molecules. The Journal of Chemical Physics. 149: 144106. PMID 30316286 DOI: 10.1063/1.5047030  0.399
2018 Tellgren EI, Laestadius A, Helgaker T, Kvaal S, Teale AM. Uniform magnetic fields in density-functional theory. The Journal of Chemical Physics. 148: 024101. PMID 29331113 DOI: 10.1063/1.5007300  0.435
2018 Reimann S, Borgoo A, Austad J, Tellgren EI, Teale AM, Helgaker T, Stopkowicz S. Kohn–Sham energy decomposition for molecules in a magnetic field Molecular Physics. 117: 97-109. DOI: 10.1080/00268976.2018.1495849  0.486
2018 Rebolini E, Teale AM, Helgaker T, Savin A, Toulouse J. Excitation energies from Görling–Levy perturbation theory along the range-separated adiabatic connection Molecular Physics. 116: 1443-1451. DOI: 10.1080/00268976.2017.1422811  0.447
2017 Irons TJP, Furness JW, Ryley MS, Zemen J, Helgaker T, Teale AM. Connections between variation principles at the interface of wave-function and density-functional theories. The Journal of Chemical Physics. 147: 134107. PMID 28987103 DOI: 10.1063/1.4985883  0.418
2017 Reimann S, Borgoo A, Tellgren EI, Teale AM, Helgaker T. Magnetic-Field Density-Functional Theory (BDFT): Lessons from the Adiabatic Connection. Journal of Chemical Theory and Computation. PMID 28768100 DOI: 10.1021/Acs.Jctc.7B00295  0.437
2017 Adamowicz L, Stanke M, Tellgren E, Helgaker T. Explicitly-correlated non-born-oppenheimer calculations of the HD molecule in a strong magnetic field Chemical Physics Letters. 682: 87-90. DOI: 10.1016/J.Cplett.2017.06.016  0.458
2016 Kumar C, Kjærgaard T, Helgaker T, Fliegl H. Nuclei-selected atomic-orbital response-theory formulation for the calculation of NMR shielding tensors using density-fitting. The Journal of Chemical Physics. 145: 234108. PMID 28010085 DOI: 10.1063/1.4972212  0.484
2016 Helgaker T, Jaszuński M, Świder P. Calculation of NMR Spin-Spin Coupling Constants in Strychnine. The Journal of Organic Chemistry. 81: 11496-11500. PMID 27802051 DOI: 10.1021/Acs.Joc.6B02157  0.414
2016 Rebolini E, Izsák R, Reine SS, Helgaker T, Pedersen TB. Comparison of three efficient approximate exact-exchange algorithms: chain-of-spheres, pair-atomic resolution of the identity, and the auxiliary density matrix method. Journal of Chemical Theory and Computation. PMID 27224306 DOI: 10.1021/Acs.Jctc.6B00074  0.386
2016 Furness JW, Ekström U, Helgaker T, Teale AM. Electron localisation function in current-density-functional theory Molecular Physics. 1-8. DOI: 10.1080/00268976.2015.1133859  0.454
2016 Teale AM, Helgaker T, Savin A. Alternative Representations of the Correlation Energy in Density-Functional Theory: A Kinetic-Energy Based Adiabatic Connection Journal of the Chinese Chemical Society. 63: 121-128. DOI: 10.1002/Jccs.201500132  0.391
2015 Furness JW, Verbeke J, Tellgren EI, Stopkowicz S, Ekström U, Helgaker T, Teale AM. Current Density Functional Theory Using Meta-Generalized Gradient Exchange-Correlation Functionals. Journal of Chemical Theory and Computation. 11: 4169-81. PMID 26575912 DOI: 10.1021/Acs.Jctc.5B00535  0.799
2015 Peach MJ, Teale AM, Helgaker T, Tozer DJ. Fractional Electron Loss in Approximate DFT and Hartree-Fock Theory. Journal of Chemical Theory and Computation. 11: 5262-8. PMID 26574320 DOI: 10.1021/Acs.Jctc.5B00804  0.622
2015 Kvaal S, Helgaker T. Ground-state densities from the Rayleigh-Ritz variation principle and from density-functional theory. The Journal of Chemical Physics. 143: 184106. PMID 26567645 DOI: 10.1063/1.4934797  0.376
2015 Stopkowicz S, Gauss J, Lange KK, Tellgren EI, Helgaker T. Coupled-cluster theory for atoms and molecules in strong magnetic fields. The Journal of Chemical Physics. 143: 074110. PMID 26298118 DOI: 10.1063/1.4928056  0.815
2015 Reimann S, Ekström U, Stopkowicz S, Teale AM, Borgoo A, Helgaker T. The importance of current contributions to shielding constants in density-functional theory. Physical Chemistry Chemical Physics : Pccp. PMID 26123927 DOI: 10.1039/C5Cp02682B  0.788
2015 Ryding MJ, Izsák R, Merlot P, Reine S, Helgaker T, Uggerud E. Geometry of the magic number H(+)(H2O)21 water cluster by proxy. Physical Chemistry Chemical Physics : Pccp. 17: 5466-73. PMID 25620033 DOI: 10.1039/C4Cp05246C  0.301
2015 Hoffmann MR, Helgaker T. Use of density functional theory orbitals in the GVVPT2 variant of second-order multistate multireference perturbation theory. The Journal of Physical Chemistry. A. 119: 1548-53. PMID 25229307 DOI: 10.1021/Jp507554V  0.477
2015 Rebolini E, Toulouse J, Teale AM, Helgaker T, Savin A. Calculating excitation energies by extrapolation along adiabatic connections Physical Review a - Atomic, Molecular, and Optical Physics. 91. DOI: 10.1103/Physreva.91.032519  0.376
2015 Cheng CY, Ryley MS, Peach MJG, Tozer DJ, Helgaker T, Teale AM. Molecular properties in the Tamm-Dancoff approximation: Indirect nuclear spin-spin coupling constants Molecular Physics. 113: 1937-1951. DOI: 10.1080/00268976.2015.1024182  0.695
2015 Rebolini E, Toulouse J, Teale AM, Helgaker T, Savin A. Excited states from range-separated density-functional perturbation theory Molecular Physics. DOI: 10.1080/00268976.2015.1011248  0.44
2015 Adamowicz L, Tellgren EI, Helgaker T. Non-Born-Oppenheimer calculations of the HD molecule in a strong magnetic field Chemical Physics Letters. 639: 295-299. DOI: 10.1016/J.Cplett.2015.09.051  0.462
2015 Mennucci B, Eisenstein O, Fliegl H, Hopmann KH, Helgaker T, Ruud K. FemEx - Female excellence in theoretical and computational chemistry International Journal of Quantum Chemistry. 115: 1195-1196. DOI: 10.1002/Qua.24961  0.483
2014 Ringholm M, Jonsson D, Bast R, Gao B, Thorvaldsen AJ, Ekström U, Helgaker T, Ruud K. Analytic cubic and quartic force fields using density-functional theory. The Journal of Chemical Physics. 140: 034103. PMID 25669359 DOI: 10.1063/1.4861003  0.82
2014 Tellgren EI, Teale AM, Furness JW, Lange KK, Ekström U, Helgaker T. Non-perturbative calculation of molecular magnetic properties within current-density functional theory. The Journal of Chemical Physics. 140: 034101. PMID 25669357 DOI: 10.1063/1.4861427  0.462
2014 Aidas K, Angeli C, Bak KL, Bakken V, Bast R, Boman L, Christiansen O, Cimiraglia R, Coriani S, Dahle P, Dalskov EK, Ekström U, Enevoldsen T, Eriksen JJ, Ettenhuber P, ... ... Helgaker T, et al. The Dalton quantum chemistry program system. Wiley Interdisciplinary Reviews. Computational Molecular Science. 4: 269-284. PMID 25309629 DOI: 10.1002/Wcms.1172  0.792
2014 Merlot P, Izsák R, Borgoo A, Kjærgaard T, Helgaker T, Reine S. Charge-constrained auxiliary-density-matrix methods for the Hartree-Fock exchange contribution. The Journal of Chemical Physics. 141: 094104. PMID 25194361 DOI: 10.1063/1.4894267  0.431
2014 Smalø HS, Rybkin VV, Klopper W, Helgaker T, Uggerud E. Mechanochemistry: the effect of dynamics. The Journal of Physical Chemistry. A. 118: 7683-94. PMID 25105205 DOI: 10.1021/Jp504959Z  0.371
2014 Rebolini E, Toulouse J, Teale AM, Helgaker T, Savin A. Excitation energies along a range-separated adiabatic connection. The Journal of Chemical Physics. 141: 044123. PMID 25084897 DOI: 10.1063/1.4890652  0.402
2014 Kvaal S, Ekström U, Teale AM, Helgaker T. Differentiable but exact formulation of density-functional theory. The Journal of Chemical Physics. 140: 18A518. PMID 24832326 DOI: 10.1063/1.4867005  0.321
2014 Tellgren EI, Kvaal S, Helgaker T. FermionN-representability for prescribed density and paramagnetic current density Physical Review A. 89. DOI: 10.1103/Physreva.89.012515  0.335
2013 Helgaker T, Gauss J, Cazzoli G, Puzzarini C. 33S hyperfine interactions in H2S and SO2 and revision of the sulfur nuclear magnetic shielding scale. The Journal of Chemical Physics. 139: 244308. PMID 24387371 DOI: 10.1063/1.4849177  0.584
2013 Stoyanova A, Teale AM, Toulouse J, Helgaker T, Fromager E. Alternative separation of exchange and correlation energies in multi-configuration range-separated density-functional theory. The Journal of Chemical Physics. 139: 134113. PMID 24116558 DOI: 10.1063/1.4822135  0.723
2013 Rekkedal J, Coriani S, Iozzi MF, Teale AM, Helgaker T, Pedersen TB. Communication: Analytic gradients in the random-phase approximation. The Journal of Chemical Physics. 139: 081101. PMID 24006965 DOI: 10.1063/1.4819399  0.391
2013 Przybytek M, Helgaker T. The accuracy of the Gaussian-and-finite-element-Coulomb (GFC) method for the calculation of Coulomb integrals. The Journal of Chemical Physics. 139: 054114. PMID 23927250 DOI: 10.1063/1.4817002  0.425
2013 Rybkin VV, Ekström U, Helgaker T. Internal-to-Cartesian back transformation of molecular geometry steps using high-order geometric derivatives. Journal of Computational Chemistry. 34: 1842-9. PMID 23703109 DOI: 10.1002/Jcc.23327  0.315
2013 Merlot P, Kjærgaard T, Helgaker T, Lindh R, Aquilante F, Reine S, Pedersen TB. Attractive electron-electron interactions within robust local fitting approximations. Journal of Computational Chemistry. 34: 1486-96. PMID 23553369 DOI: 10.1002/Jcc.23284  0.423
2013 Teale AM, Lutnæs OB, Helgaker T, Tozer DJ, Gauss J. Benchmarking density-functional theory calculations of NMR shielding constants and spin-rotation constants using accurate coupled-cluster calculations. The Journal of Chemical Physics. 138: 024111. PMID 23320672 DOI: 10.1063/1.4773016  0.748
2013 Rybkin VV, Simakov AO, Bakken V, Reine S, Kjaergaard T, Helgaker T, Uggerud E. Insights into the dynamics of evaporation and proton migration in protonated water clusters from large-scale Born-Oppenheimer direct dynamics. Journal of Computational Chemistry. 34: 533-44. PMID 23108605 DOI: 10.1002/Jcc.23162  0.346
2012 Lange KK, Tellgren EI, Hoffmann MR, Helgaker T. A paramagnetic bonding mechanism for diatomics in strong magnetic fields. Science (New York, N.Y.). 337: 327-31. PMID 22822146 DOI: 10.1126/Science.1219703  0.381
2012 Tellgren EI, Reine SS, Helgaker T. Analytical GIAO and hybrid-basis integral derivatives: application to geometry optimization of molecules in strong magnetic fields. Physical Chemistry Chemical Physics : Pccp. 14: 9492-9. PMID 22653039 DOI: 10.1039/C2Cp40965H  0.405
2012 Helgaker T, Coriani S, Jørgensen P, Kristensen K, Olsen J, Ruud K. Recent advances in wave function-based methods of molecular-property calculations. Chemical Reviews. 112: 543-631. PMID 22236047 DOI: 10.1021/Cr2002239  0.571
2012 Tellgren EI, Kvaal S, Sagvolden E, Ekström U, Teale AM, Helgaker T. Choice of basic variables in current-density-functional theory Physical Review a - Atomic, Molecular, and Optical Physics. 86. DOI: 10.1103/Physreva.86.062506  0.404
2012 Helgaker T, Jaszuński M, Garbacz P, Jackowski K. The NMR indirect nuclear spin–spin coupling constant of the HD molecule Molecular Physics. 110: 2611-2617. DOI: 10.1080/00268976.2012.729097  0.427
2012 Middendorf N, Höfener S, Klopper W, Helgaker T. Calculation of the two-electron Darwin term using explicitly correlated wave functions Chemical Physics. 401: 146-151. DOI: 10.1016/J.Chemphys.2011.10.035  0.446
2012 Onishi T, Helgaker T. A theoretical study on the hydrogen transport mechanism in SrTiO3 perovskite. II. Scandium doping at titanium site International Journal of Quantum Chemistry. 113: 599-604. DOI: 10.1002/Qua.24086  0.344
2011 Strømsheim MD, Kumar N, Coriani S, Sagvolden E, Teale AM, Helgaker T. Dispersion interactions in density-functional theory: an adiabatic-connection analysis. The Journal of Chemical Physics. 135: 194109. PMID 22112068 DOI: 10.1063/1.3660357  0.463
2011 Iozzi MF, Helgaker T, Uggerud E. Influence of external force on properties and reactivity of disulfide bonds. The Journal of Physical Chemistry. A. 115: 2308-15. PMID 21366304 DOI: 10.1021/Jp109428G  0.351
2011 Bast R, Ekström U, Gao B, Helgaker T, Ruud K, Thorvaldsen AJ. The ab initio calculation of molecular electric, magnetic and geometric properties. Physical Chemistry Chemical Physics : Pccp. 13: 2627-51. PMID 21180690 DOI: 10.1039/C0Cp01647K  0.836
2011 Klopper W, Teale AM, Coriani S, Pedersen TB, Helgaker T. Spin flipping in ring-coupled-cluster-doubles theory Chemical Physics Letters. 510: 147-153. DOI: 10.1016/J.Cplett.2011.04.101  0.402
2011 Bast R, Ruud K, Rizzo A, Helgaker T. Relativistic four-component calculations of Buckingham birefringence using London atomic orbitals Theoretical Chemistry Accounts. 129: 685-699. DOI: 10.1007/S00214-011-0939-3  0.813
2011 Reine S, Helgaker T, Lindh R. Multi-electron integrals Wiley Interdisciplinary Reviews: Computational Molecular Science. 2: 290-303. DOI: 10.1002/Wcms.78  0.306
2010 Teale AM, Coriani S, Helgaker T. Range-dependent adiabatic connections. The Journal of Chemical Physics. 133: 164112. PMID 21033780 DOI: 10.1063/1.3488100  0.394
2010 Reine S, Krapp A, Iozzi MF, Bakken V, Helgaker T, Pawłowski F, Sałek P. An efficient density-functional-theory force evaluation for large molecular systems. The Journal of Chemical Physics. 133: 044102. PMID 20687628 DOI: 10.1063/1.3459061  0.46
2010 Teale AM, Coriani S, Helgaker T. Accurate calculation and modeling of the adiabatic connection in density functional theory. The Journal of Chemical Physics. 132: 164115. PMID 20441266 DOI: 10.1063/1.3380834  0.483
2010 Lutnæs OB, Helgaker T, Jaszuński M. Spin–spin coupling constants and triplet instabilities in Kohn–Sham theory Molecular Physics. 108: 2579-2590. DOI: 10.1080/00268976.2010.513344  0.456
2009 Jansík B, Høst S, Johansson MP, Olsen J, Jørgensen P, Helgaker T. Robust and Reliable Multilevel Minimization of the Kohn-Sham Energy. Journal of Chemical Theory and Computation. 5: 1027-32. PMID 26609611 DOI: 10.1021/Ct800562H  0.41
2009 Friedrich J, Coriani S, Helgaker T, Dolg M. Implementation of the incremental scheme for one-electron first-order properties in coupled-cluster theory. The Journal of Chemical Physics. 131: 154102. PMID 20568842 DOI: 10.1063/1.3243864  0.393
2009 Jansík B, Høst S, Johansson MP, Olsen J, Jørgensen P, Helgaker T. A stepwise atomic, valence-molecular, and full-molecular optimisation of the Hartree-Fock/Kohn-Sham energy. Physical Chemistry Chemical Physics : Pccp. 11: 5805-13. PMID 19842498 DOI: 10.1039/B901987A  0.377
2009 Lutnaes OB, Teale AM, Helgaker T, Tozer DJ, Ruud K, Gauss J. Benchmarking density-functional-theory calculations of rotational g tensors and magnetizabilities using accurate coupled-cluster calculations. The Journal of Chemical Physics. 131: 144104. PMID 19831430 DOI: 10.1063/1.3242081  0.792
2009 Tellgren EI, Helgaker T, Soncini A. Non-perturbative magnetic phenomena in closed-shell paramagnetic molecules. Physical Chemistry Chemical Physics : Pccp. 11: 5489-98. PMID 19551219 DOI: 10.1039/B822262B  0.401
2009 Teale AM, Coriani S, Helgaker T. The calculation of adiabatic-connection curves from full configuration-interaction densities: two-electron systems. The Journal of Chemical Physics. 130: 104111. PMID 19292527 DOI: 10.1063/1.3082285  0.468
2009 Iozzi MF, Helgaker T, Uggerud E. Assessment of theoretical methods for the determination of the mechanochemical strength of covalent bonds Molecular Physics. 107: 2537-2546. DOI: 10.1080/00268970903401041  0.454
2009 Höfener S, Tew DP, Klopper W, Helgaker T. The geminal basis in explicitly correlated wave functions Chemical Physics. 356: 25-30. DOI: 10.1016/J.Chemphys.2008.10.022  0.371
2008 Kristensen K, Jørgensen P, Thorvaldsen AJ, Helgaker T. Efficient elimination of response parameters in molecular property calculations for variational and nonvariational energies. The Journal of Chemical Physics. 129: 214103. PMID 19063540 DOI: 10.1063/1.3023123  0.729
2008 Tellgren EI, Soncini A, Helgaker T. Nonperturbative ab initio calculations in strong magnetic fields using London orbitals. The Journal of Chemical Physics. 129: 154114. PMID 19045183 DOI: 10.1063/1.2996525  0.481
2008 Reine S, Tellgren E, Krapp A, Kjaergaard T, Helgaker T, Jansik B, Host S, Salek P. Variational and robust density fitting of four-center two-electron integrals in local metrics. The Journal of Chemical Physics. 129: 104101. PMID 19044902 DOI: 10.1063/1.2956507  0.4
2008 Soncini A, Teale AM, Helgaker T, De Proft F, Tozer DJ. Maps of current density using density-functional methods. The Journal of Chemical Physics. 129: 074101. PMID 19044754 DOI: 10.1063/1.2969104  0.673
2008 Høst S, Jansík B, Olsen J, Jørgensen P, Reine S, Helgaker T. A ground-state-directed optimization scheme for the Kohn-Sham energy. Physical Chemistry Chemical Physics : Pccp. 10: 5344-8. PMID 18766229 DOI: 10.1039/B807639A  0.385
2008 Kjaergaard T, Jørgensen P, Olsen J, Coriani S, Helgaker T. Hartree-Fock and Kohn-Sham time-dependent response theory in a second-quantization atomic-orbital formalism suitable for linear scaling. The Journal of Chemical Physics. 129: 054106. PMID 18698887 DOI: 10.1063/1.2961039  0.456
2008 Dahle P, Helgaker T, Jonsson D, Taylor PR. Second-order Møller-Plesset calculations on the water molecule using Gaussian-type orbital and Gaussian-type geminal theory. Physical Chemistry Chemical Physics : Pccp. 10: 3377-82. PMID 18535720 DOI: 10.1039/B803577F  0.747
2008 Peach MJ, Benfield P, Helgaker T, Tozer DJ. Excitation energies in density functional theory: an evaluation and a diagnostic test. The Journal of Chemical Physics. 128: 044118. PMID 18247941 DOI: 10.1063/1.2831900  0.607
2008 Bast R, Hesselmann A, Sałek P, Helgaker T, Saue T. Static and frequency-dependent dipole-dipole polarizabilities of all closed-shell atoms up to radium: a four-component relativistic DFT study. Chemphyschem : a European Journal of Chemical Physics and Physical Chemistry. 9: 445-53. PMID 18224633 DOI: 10.1002/Cphc.200700504  0.759
2008 Lutnæs OB, Helgaker T, Jaszuński M. Density-functional calculations of the nuclear magnetic shielding and indirect nuclear spin–spin coupling constants of three isomers of C20 Molecular Physics. 106: 2357-2365. DOI: 10.1080/00268970802467994  0.423
2008 Helgaker T, Klopper W, Tew DP. Quantitative quantum chemistry Molecular Physics. 106: 2107-2143. DOI: 10.1080/00268970802258591  0.438
2008 Rizzo A, Cappelli C, Jansík B, Jonsson D, Sałek P, Coriani S, Ågren H, Wilson DJD, Helgaker T, Junquera–Hernández JM, Merás AMJSd, Sánchez-Marín J. Erratum: “Density-functional and electron correlated study of five linear birefringences—Kerr, Cotton–Mouton, Buckingham, Jones and magnetoelectric—in gaseous benzene” [J. Chem. Phys. 121, 8814 (2004)]; “Density-functional study of electric and magnetic properties of hexafluorobenzene in the vapor phase” [J. Chem. Phys. 122, 234314 (2005)]; and “A computational study of some electric and magnetic properties of gaseous BF3 and BCl3” [J. Chem. Phys. 123, 114307 (2005)] Journal of Chemical Physics. 129: 39901. DOI: 10.1063/1.2946699  0.714
2008 Helgaker T, Jaszuński M, Pecul M. The quantum-chemical calculation of NMR indirect spin–spin coupling constants Progress in Nuclear Magnetic Resonance Spectroscopy. 53: 249-268. DOI: 10.1016/J.Pnmrs.2008.02.002  0.654
2007 Helgaker T, Jaszuński M. Density-Functional and Coupled-Cluster Singles-and-Doubles Calculations of the Nuclear Shielding and Indirect Nuclear Spin-Spin Coupling Constants of o-Benzyne. Journal of Chemical Theory and Computation. 3: 86-94. PMID 26627155 DOI: 10.1021/Ct600234N  0.448
2007 Peach MJ, Tellgren EI, Sa?ek P, Helgaker T, Tozer DJ. Structural and electronic properties of polyacetylene and polyyne from hybrid and Coulomb-attenuated density functionals. The Journal of Physical Chemistry. A. 111: 11930-5. PMID 17963369 DOI: 10.1021/Jp0754839  0.63
2007 Skomorowski W, Pecul M, Sałek P, Helgaker T. Electronic circular dichroism of disulphide bridge: ab initio quantum-chemical calculations. The Journal of Chemical Physics. 127: 085102. PMID 17764301 DOI: 10.1063/1.2759203  0.726
2007 Reine S, Tellgren E, Helgaker T. A unified scheme for the calculation of differentiated and undifferentiated molecular integrals over solid-harmonic Gaussians. Physical Chemistry Chemical Physics : Pccp. 9: 4771-9. PMID 17712455 DOI: 10.1039/B705594C  0.361
2007 Dahle P, Helgaker T, Jonsson D, Taylor PR. Accurate quantum-chemical calculations using Gaussian-type geminal and Gaussian-type orbital basis sets: applications to atoms and diatomics. Physical Chemistry Chemical Physics : Pccp. 9: 3112-26. PMID 17612735 DOI: 10.1039/B616488A  0.784
2007 Coriani S, Høst S, Jansík B, Thøgersen L, Olsen J, Jørgensen P, Reine S, Pawłowski F, Helgaker T, Sałek P. Linear-scaling implementation of molecular response theory in self-consistent field electronic-structure theory. The Journal of Chemical Physics. 126: 154108. PMID 17461615 DOI: 10.1063/1.2715568  0.504
2007 Jansík B, Host S, Jorgensen P, Olsen J, Helgaker T. Linear-scaling symmetric square-root decomposition of the overlap matrix. The Journal of Chemical Physics. 126: 124104. PMID 17411105 DOI: 10.1063/1.2709881  0.363
2007 Sałek P, Høst S, Thøgersen L, Jørgensen P, Manninen P, Olsen J, Jansík B, Reine S, Pawłowski F, Tellgren E, Helgaker T, Coriani S. Linear-scaling implementation of molecular electronic self-consistent field theory. The Journal of Chemical Physics. 126: 114110. PMID 17381199 DOI: 10.1063/1.2464111  0.406
2007 Tew DP, Klopper W, Helgaker T. Electron correlation: the many-body problem at the heart of chemistry. Journal of Computational Chemistry. 28: 1307-20. PMID 17269126 DOI: 10.1002/Jcc.20581  0.381
2006 Teale AM, Helgaker T, Tozer DJ. Rotational g Tensors Calculated Using Hybrid Exchange-Correlation Functionals with the Optimized Effective Potential Approach. Journal of Chemical Theory and Computation. 2: 827-34. PMID 26626689 DOI: 10.1021/Ct060038N  0.678
2006 Helgaker T, Hennum AC, Klopper W. A second-quantization framework for the unified treatment of relativistic and nonrelativistic molecular perturbations by response theory. The Journal of Chemical Physics. 125: 24102. PMID 16848572 DOI: 10.1063/1.2198527  0.413
2006 Peach MJ, Helgaker T, Sa?ek P, Keal TW, Lutnaes OB, Tozer DJ, Handy NC. Assessment of a Coulomb-attenuated exchange-correlation energy functional. Physical Chemistry Chemical Physics : Pccp. 8: 558-62. PMID 16482297 DOI: 10.1039/B511865D  0.715
2006 Paterson MJ, Christiansen O, Pawłowski F, Jorgensen P, Hättig C, Helgaker T, Sałek P. Benchmarking two-photon absorption with CC3 quadratic response theory, and comparison with density-functional response theory. The Journal of Chemical Physics. 124: 054322. PMID 16468884 DOI: 10.1063/1.2163874  0.444
2006 Coriani S, Haaland A, Helgaker T, Jørgensen P. The equilibrium structure of ferrocene. Chemphyschem : a European Journal of Chemical Physics and Physical Chemistry. 7: 245-9. PMID 16404766 DOI: 10.1002/Cphc.200500339  0.456
2006 Wilson§ DJD, Helgaker T, Rizzo A. The magnetizability, rotational g tensor and quadrupole moment of the boron trihalides Molecular Physics. 104: 847-856. DOI: 10.1080/00268970500418117  0.482
2006 Lutnæs OB, Teale AM, Helgaker T, Tozer DJ. Rotational g tensors calculated using hybrid exchange-correlation functionals with the optimized effective potential approach Journal of Chemical Theory and Computation. 2: 827-834. DOI: 10.1021/ct060038n  0.566
2006 Keal TW, Helgaker T, Sa?ek P, Tozer DJ. Choice of exchange-correlation functional for computing NMR indirect spin-spin coupling constants Chemical Physics Letters. 425: 163-166. DOI: 10.1016/J.Cplett.2006.05.032  0.599
2006 Ferrighi L, Frediani L, Cappelli C, Sałek P, Ågren H, Helgaker T, Ruud K. Density-functional-theory study of the electric-field-induced second harmonic generation (EFISHG) of push-pull phenylpolyenes in solution Chemical Physics Letters. 425: 267-272. DOI: 10.1016/J.Cplett.2006.04.112  0.818
2005 Wilson DJ, Mohn CE, Helgaker T. The Rotational g Tensor as a Benchmark for Density-Functional Theory Calculations of Molecular Magnetic Properties. Journal of Chemical Theory and Computation. 1: 877-88. PMID 26641904 DOI: 10.1021/Ct050101T  0.499
2005 Cybulski H, Pecul M, Helgaker T, Jaszuński M. Theoretical studies of nuclear magnetic resonance parameters for the proton-exchange pathways in porphyrin and porphycene. The Journal of Physical Chemistry. A. 109: 4162-71. PMID 16833741 DOI: 10.1021/Jp045440H  0.694
2005 Rizzo A, Cappelli C, Junquera-Hernández JM, de Merás AM, Sánchez-Marín J, Wilson DJ, Helgaker T. A computational study of some electric and magnetic properties of gaseous BF3 and BCl3. The Journal of Chemical Physics. 123: 114307. PMID 16392559 DOI: 10.1063/1.2034487  0.485
2005 Olsen J, Jørgensen P, Helgaker T, Oddershede J. Quadratic response functions in a second-order polarization propagator framework. The Journal of Physical Chemistry. A. 109: 11618-28. PMID 16354055 DOI: 10.1021/Jp054207W  0.389
2005 Rudberg E, Sałek P, Helgaker T, Agren H. Calculations of two-photon charge-transfer excitations using Coulomb-attenuated density-functional theory. The Journal of Chemical Physics. 123: 184108. PMID 16292900 DOI: 10.1063/1.2104367  0.525
2005 Coriani S, Marchesan D, Gauss J, Hättig C, Helgaker T, Jørgensen P. The accuracy of ab initio molecular geometries for systems containing second-row atoms. The Journal of Chemical Physics. 123: 184107. PMID 16292899 DOI: 10.1063/1.2104387  0.646
2005 Thøgersen L, Olsen J, Köhn A, Jørgensen P, Sa?ek P, Helgaker T. The trust-region self-consistent field method in Kohn-Sham density-functional theory. The Journal of Chemical Physics. 123: 074103. PMID 16229555 DOI: 10.1063/1.1989311  0.367
2005 Rizzo A, Cappelli C, Jansík B, Jonsson D, Sałek P, Coriani S, Wilson DJ, Helgaker T, Agren H. Density-functional theory study of electric and magnetic properties of hexafluorobenzene in the vapor phase. The Journal of Chemical Physics. 122: 234314. PMID 16008448 DOI: 10.1063/1.1935513  0.758
2005 Sałek P, Helgaker T, Vahtras O, Ågren H, Jonsson D, Gauss J. A comparison of density-functional-theory and coupled-cluster frequency-dependent polarizabilities and hyperpolarizabilities Molecular Physics. 103: 439-450. DOI: 10.1080/00268970412331319254  0.683
2005 Mohn CE, Wilson DJD, Lutnæs OB, Helgaker T, Ruud K. The Rotational g Tensor as a Benchmark for Ab Initio Molecular Property Calculations Advances in Quantum Chemistry. 50: 77-90. DOI: 10.1016/S0065-3276(05)50005-4  0.658
2005 Salek P, Helgaker T, Saue T. Linear response at the 4-component relativistic density-functional level: application to the frequency-dependent dipole polarizability of Hg, AuH and PtH2 Chemical Physics. 311: 187-201. DOI: 10.1016/J.Chemphys.2004.10.011  0.496
2004 Bakken V, Helgaker T, Uggerud E. Models of fragmentations induced by electron attachment to protonated peptides. European Journal of Mass Spectrometry (Chichester, England). 10: 625-38. PMID 15531796 DOI: 10.1255/Ejms.665  0.352
2004 Coriani S, Helgaker T, Jørgensen P, Klopper W. A closed-shell coupled-cluster treatment of the Breit-Pauli first-order relativistic energy correction. The Journal of Chemical Physics. 121: 6591-8. PMID 15473713 DOI: 10.1063/1.1788634  0.474
2004 Watson MA, Sa?ek P, Macak P, Jaszu?ski M, Helgaker T. The calculation of indirect nuclear spin-spin coupling constants in large molecules. Chemistry (Weinheim An Der Bergstrasse, Germany). 10: 4627-39. PMID 15378642 DOI: 10.1002/Chem.200306065  0.332
2004 Ruden TA, Helgaker T, Jørgensen P, Olsen J. Coupled-cluster connected quadruples and quintuples corrections to the harmonic vibrational frequencies and equilibrium bond distances of HF, N(2), F(2), and CO. The Journal of Chemical Physics. 121: 5874-84. PMID 15367015 DOI: 10.1063/1.1780155  0.342
2004 Lutnaes OB, Ruden TA, Helgaker T. The performance of hybrid density functional theory for the calculation of indirect nuclear spin-spin coupling constants in substituted hydrocarbons. Magnetic Resonance in Chemistry : Mrc. 42: S117-27. PMID 15366047 DOI: 10.1002/Mrc.1457  0.393
2004 Jensen F, Helgaker T. Polarization consistent basis sets. V. The elements Si-Cl. The Journal of Chemical Physics. 121: 3463-70. PMID 15303910 DOI: 10.1063/1.1756866  0.468
2004 Watson MA, Sałek P, Macak P, Helgaker T. Linear-scaling formation of Kohn-Sham Hamiltonian: application to the calculation of excitation energies and polarizabilities of large molecular systems. The Journal of Chemical Physics. 121: 2915-31. PMID 15291602 DOI: 10.1063/1.1771639  0.462
2004 Soncini A, Lazzeretti P, Bakken V, Helgaker T. Calculation of electric dipole hypershieldings at the nuclei in the Hellmann-Feynman approximation. The Journal of Chemical Physics. 120: 3142-51. PMID 15268466 DOI: 10.1063/1.1630016  0.424
2004 Watson MA, Handy NC, Cohen AJ, Helgaker T. Density-functional generalized-gradient and hybrid calculations of electromagnetic properties using Slater basis sets. The Journal of Chemical Physics. 120: 7252-61. PMID 15267634 DOI: 10.1063/1.1668633  0.64
2004 Norman P, Ruud K, Helgaker T. Density-functional theory calculations of optical rotatory dispersion in the nonresonant and resonant frequency regions. The Journal of Chemical Physics. 120: 5027-35. PMID 15267368 DOI: 10.1063/1.1647515  0.629
2004 Thøgersen L, Olsen J, Yeager D, Jørgensen P, Sałek P, Helgaker T. The trust-region self-consistent field method: towards a black-box optimization in Hartree-Fock and Kohn-Sham theories. The Journal of Chemical Physics. 121: 16-27. PMID 15260518 DOI: 10.1063/1.1755673  0.38
2004 Klopper W, Coriani S, Helgaker T, Jørgensen P. First-order relativistic corrections to response properties: the hyperpolarizability of the Ne atom Journal of Physics B: Atomic, Molecular and Optical Physics. 37: 3753-3763. DOI: 10.1088/0953-4075/37/18/015  0.458
2004 Bruun J, Helgaker T, Jensen * F. A comparison of polarization and bond functions for density functional calculations Molecular Physics. 102: 2559-2562. DOI: 10.1080/0026897042000275026  0.383
2004 Watson MA, Sałek P, Macak P, Helgaker T. Linear-scaling formation of Kohn-Sham Hamiltonian: Application to the calculation of excitation energies and polarizabilities of large molecular systems Journal of Chemical Physics. 121: 2915-2931. DOI: 10.1063/1.1771639  0.37
2004 Pecul M, Ruud K, Rizzo A, Helgaker T. Conformational Effects on the Optical Rotation of Alanine and Proline The Journal of Physical Chemistry A. 108: 4269-4276. DOI: 10.1021/Jp037663Y  0.726
2004 Ratajczyk T, Pecul M, Sadlej J, Helgaker T. Potential Energy and Spin−Spin Coupling Constants Surface of Glycolaldehyde The Journal of Physical Chemistry A. 108: 2758-2769. DOI: 10.1021/Jp0375315  0.714
2004 Keal TW, Tozer DJ, Helgaker T. GIAO shielding constants and indirect spin-spin coupling constants: Performance of density functional methods Chemical Physics Letters. 391: 374-379. DOI: 10.1016/J.Cplett.2004.04.108  0.638
2004 Pecul M, Ruud K, Helgaker T. Density functional theory calculation of electronic circular dichroism using London orbitals Chemical Physics Letters. 388: 110-119. DOI: 10.1016/J.Cplett.2004.03.008  0.791
2004 Ruden TA, Helgaker T, Jaszuński M. The NMR indirect nuclear spin-spin coupling constants for some small rigid hydrocarbons: molecular equilibrium values and vibrational corrections Chemical Physics. 296: 53-62. DOI: 10.1016/J.Chemphys.2003.08.018  0.51
2004 Bakken V, Helgaker T. The expansion of hydrogen states in Gaussian orbitals Theoretical Chemistry Accounts. 112. DOI: 10.1007/S00214-004-0573-4  0.392
2004 Helgaker T, Ruden TA, Jørgensen P, Olsen J, Klopper W. A priori calculation of molecular properties to chemical accuracy Journal of Physical Organic Chemistry. 17: 913-933. DOI: 10.1002/Poc.841  0.516
2003 Pecul M, Helgaker T. The Spin–Spin Coupling Constants in Ethane, Methanol and Methylamine: A Comparison of DFT, MCSCF and CCSD Results International Journal of Molecular Sciences. 4: 143-157. DOI: 10.3390/I4030143  0.717
2003 JASZUNSKI M, RUUD K, HELGAKER T. Density-functional theory calculation of the nuclear magnetic resonance indirect nuclear spin—spin coupling constants in C60 Molecular Physics. 101: 1997-2002. DOI: 10.1080/0026897031000109301  0.601
2003 Tunell I, Rinkevicius Z, Vahtras O, Sałek P, Helgaker T, Ågren H. Density functional theory of nonlinear triplet response properties with applications to phosphorescence The Journal of Chemical Physics. 119: 11024-11034. DOI: 10.1063/1.1622926  0.559
2003 Cybulski H, Pecul M, Sadlej J, Helgaker T. Characterization of dihydrogen-bonded D–H⋯H–A complexes on the basis of infrared and magnetic resonance spectroscopic parameters The Journal of Chemical Physics. 119: 5094-5104. DOI: 10.1063/1.1597633  0.665
2003 Ruden TA, Taylor PR, Helgaker T. Automated calculation of fundamental frequencies: Application to AlH3 using the coupled-cluster singles-and-doubles with perturbative triples method Journal of Chemical Physics. 119: 1951-1960. DOI: 10.1063/1.1583671  0.599
2003 Hald K, Halkier A, Jørgensen P, Coriani S, Hättig C, Helgaker T. Publisher’s Note: “A Lagrangian, integral-density direct formulation and implementation of the analytic CCSD and CCSD(T) gradients” [J. Chem. Phys. 118, 2985 (2003)] The Journal of Chemical Physics. 118: 11335-11335. DOI: 10.1063/1.1580103  0.311
2003 Ruden TA, Lutnæs OB, Helgaker T, Ruud K. Vibrational corrections to indirect nuclear spin–spin coupling constants calculated by density-functional theory The Journal of Chemical Physics. 118: 9572-9581. DOI: 10.1063/1.1569846  0.674
2003 Pawłowski F, Halkier A, Jørgensen P, Bak KL, Helgaker T, Klopper W. Accuracy of spectroscopic constants of diatomic molecules from ab initio calculations The Journal of Chemical Physics. 118: 2539. DOI: 10.1063/1.1533032  0.455
2003 Hald K, Halkier A, Jørgensen P, Coriani S, Hättig C, Helgaker T. A Lagrangian, integral-density direct formulation and implementation of the analytic CCSD and CCSD(T) gradients The Journal of Chemical Physics. 118: 2985-2998. DOI: 10.1063/1.1531106  0.376
2003 Sałek P, Vahtras O, Guo J, Luo Y, Helgaker T, Ågren H. Calculations of two-photon absorption cross sections by means of density-functional theory Chemical Physics Letters. 374: 446-452. DOI: 10.1016/S0009-2614(03)00681-X  0.566
2003 Pecul M, Sadlej J, Helgaker T. Calculations of hydrogen-bond-transmitted indirect nuclear spin–spin couplings: a comparison of density-functional and ab initio methods Chemical Physics Letters. 372: 476-484. DOI: 10.1016/S0009-2614(03)00475-5  0.694
2003 Rizzo A, Ruud K, Helgaker T, Sałek P, Ågren H, Vahtras O. Sternheimer shieldings and EFG polarizabilities: a density-functional theory study Chemical Physics Letters. 372: 377-385. DOI: 10.1016/S0009-2614(03)00410-X  0.708
2003 Ruden TA, Helgaker T, Jørgensen P, Olsen J. Coupled-cluster connected-quadruples corrections to atomization energies Chemical Physics Letters. 371: 62-67. DOI: 10.1016/S0009-2614(03)00225-2  0.37
2002 Saue T, Helgaker T. Four-component relativistic Kohn-Sham theory. Journal of Computational Chemistry. 23: 814-23. PMID 12012358 DOI: 10.1002/Jcc.10066  0.509
2002 Auer AA, Helgaker T, Klopper W. Software news and updates. Basis-set completeness profiles in two dimensions. Journal of Computational Chemistry. 23: 420-5. PMID 11908505 DOI: 10.1002/Jcc.1169  0.349
2002 Sałek P, Vahtras O, Helgaker T, Ågren H. Density-functional theory of linear and nonlinear time-dependent molecular properties The Journal of Chemical Physics. 117: 9630-9645. DOI: 10.1063/1.1516805  0.579
2002 Bakken V, Helgaker T. The efficient optimization of molecular geometries using redundant internal coordinates The Journal of Chemical Physics. 117: 9160-9174. DOI: 10.1063/1.1515483  0.342
2002 Lantto P, Vaara J, Helgaker T. Spin–spin coupling tensors by density-functional linear response theory Journal of Chemical Physics. 117: 5998-6009. DOI: 10.1063/1.1502243  0.515
2002 Christiansen O, Ruden TA, Ruud K, Helgaker T. Vibronic transitions from coupled-cluster response theory: Theory and application to HSiF and H[sub 2]O The Journal of Chemical Physics. 116: 8334. DOI: 10.1063/1.1468639  0.59
2002 Pawowski F, Jørgensen P, Olsen J, Hegelund F, Helgaker T, Gauss J, Bak KL, Stanton JF. Molecular equilibrium structures from experimental rotational constants and calculated vibration-rotation interaction constants Journal of Chemical Physics. 116: 6482-6496. DOI: 10.1063/1.1459782  0.617
2002 Ruud K, Helgaker T, Bouř P. Gauge-Origin Independent Density-Functional Theory Calculations of Vibrational Raman Optical Activity The Journal of Physical Chemistry A. 106: 7448-7455. DOI: 10.1021/Jp026037I  0.645
2002 Samson CCM, Klopper W, Helgaker T. Computation of two-electron Gaussian integrals for wave functions including the correlation factor r12exp(−γr122) Computer Physics Communications. 149: 1-10. DOI: 10.1016/S0010-4655(02)00590-8  0.368
2002 Hennum AC, Helgaker T, Klopper W. Parity-violating interaction in H2O2 calculated from density-functional theory Chemical Physics Letters. 354: 274-282. DOI: 10.1016/S0009-2614(02)00111-2  0.462
2002 Ruud K, Helgaker T. Optical rotation studied by density-functional and coupled-cluster methods Chemical Physics Letters. 352: 533-539. DOI: 10.1016/S0009-2614(01)01492-0  0.593
2002 Wind P, Klopper W, Helgaker T. Second-order Møller–Plesset perturbation theory with terms linear in the interelectronic coordinates and exact evaluation of three-electron integrals Theoretical Chemistry Accounts. 107: 173-179. DOI: 10.1007/S00214-001-0318-6  0.432
2001 Larsen H, Olsen J, Jørgensen P, Helgaker T. Direct optimization of the atomic-orbital density matrix using the conjugate-gradient method with a multilevel preconditioner The Journal of Chemical Physics. 115: 9685-9697. DOI: 10.1063/1.1415083  0.411
2001 Larsen H, Helgaker T, Olsen J, Jørgensen P. Geometrical derivatives and magnetic properties in atomic-orbital density-based Hartree–Fock theory The Journal of Chemical Physics. 115: 10344. DOI: 10.1063/1.1415082  0.491
2001 Hennum AC, Klopper W, Helgaker T. Direct perturbation theory of magnetic properties and relativistic corrections for the point nuclear and Gaussian nuclear models Journal of Chemical Physics. 115: 7356-7363. DOI: 10.1063/1.1405009  0.442
2001 Bak KL, Gauss J, Jørgensen P, Olsen J, Helgaker T, Stanton JF. The accurate determination of molecular equilibrium structures Journal of Chemical Physics. 114: 6548-6556. DOI: 10.1063/1.1357225  0.584
2001 Bak KL, Halkier A, Jørgensen P, Olsen J, Helgaker T, Klopper W. Chemical accuracy from ‘Coulomb hole’ extrapolated molecular quantum-mechanical calculations Journal of Molecular Structure. 567: 375-384. DOI: 10.1016/S0022-2860(01)00566-X  0.451
2001 Wind P, Helgaker T, Klopper W. Efficient evaluation of one-center three-electron Gaussian integrals Theoretical Chemistry Accounts. 106: 280-286. DOI: 10.1007/S002140100281  0.376
2000 Olsen J, Jørgensen P, Helgaker T, Christiansen O. Divergence in Møller–Plesset theory: A simple explanation based on a two-state model The Journal of Chemical Physics. 112: 9736-9748. DOI: 10.1063/1.481611  0.312
2000 Bak KL, Jørgensen P, Olsen J, Helgaker T, Klopper W. Accuracy of atomization energies and reaction enthalpies in standard and extrapolated electronic wave function/basis set calculations The Journal of Chemical Physics. 112: 9229-9242. DOI: 10.1063/1.481544  0.473
2000 Helgaker T, Watson M, Handy NC. Analytical calculation of nuclear magnetic resonance indirect spin-spin coupling constants at the generalized gradient approximation and hybrid levels of density-functional theory Journal of Chemical Physics. 113: 9402-9409. DOI: 10.1063/1.1321296  0.647
2000 Larsen H, Joørgensen P, Olsen J, Helgaker T. Hartree–Fock and Kohn–Sham atomic-orbital based time-dependent response theory The Journal of Chemical Physics. 113: 8908-8917. DOI: 10.1063/1.1318745  0.473
2000 Coriani S, Hättig C, Jørgensen P, Helgaker T. Gauge-origin independent magneto-optical activity within coupled cluster response theory The Journal of Chemical Physics. 113: 3561-3572. DOI: 10.1063/1.1287833  0.395
2000 Helgaker T, Wilson PJ, Amos RD, Handy NC. Nuclear shielding constants by density functional theory with gauge including atomic orbitals The Journal of Chemical Physics. 113: 2983-2989. DOI: 10.1063/1.1287056  0.573
2000 Helgaker T, Wilson PJ, Amos RD, Handy NC. Nuclear shielding constants by density functional theory with gauge including atomic orbitals Journal of Chemical Physics. 113: 2983-2989. DOI: 10.1063/1.1287056  0.678
2000 Auer AA, Helgaker T, Klopper W. Accurate molecular geometries of the protonated water dimer Physical Chemistry Chemical Physics. 2: 2235-2238. DOI: 10.1039/A909189K  0.407
2000 Haaland A, Helgaker T, Ruud K, Shorokhov DJ. Should Gaseous BF3 and SiF4 Be Described as Ionic Compounds? Journal of Chemical Education. 77: 1076. DOI: 10.1021/Ed077P1076  0.588
2000 Bak KL, Jørgensen P, Olsen J, Helgaker T, Gauss J. Coupled-cluster singles, doubles and triples (CCSDT) calculations of atomization energies Chemical Physics Letters. 317: 116-122. DOI: 10.1016/S0009-2614(99)01315-9  0.57
2000 Helgaker T, Larsen H, Olsen J, Jørgensen P. Direct optimization of the AO density matrix in Hartree–Fock and Kohn–Sham theories Chemical Physics Letters. 327: 397-403. DOI: 10.1016/S0009-2614(00)00814-9  0.438
2000 Bak KL, Gauss J, Helgaker T, Jørgensen P, Olsen J. The accuracy of molecular dipole moments in standard electronic structure calculations Chemical Physics Letters. 319: 563-568. DOI: 10.1016/S0009-2614(00)00198-6  0.304
2000 Bak KL, Gauss J, Helgaker T, Jørgensen P, Olsen J. The accuracy of molecular dipole moments in standard electronic structure calculations Chemical Physics Letters. 319: 563-568. DOI: 10.1016/S0009-2614(00)00198-6  0.607
2000 Halkier A, Helgaker T, Klopper W, Olsen J. Basis-set convergence of the two-electron Darwin term Chemical Physics Letters. 319: 287-295. DOI: 10.1016/S0009-2614(00)00161-5  0.327
2000 Helgaker T, Klopper W. Perspective on "Neue Berechnung der Energie des Heliums im Grundzustande, sowie des tiefsten Terms von Ortho-Helium" Theoretical Chemistry Accounts: Theory, Computation, and Modeling (Theoretica Chimica Acta). 103: 180-181. DOI: 10.1007/S002149900051  0.436
1999 Helgaker T, Jaszuński M, Ruud K. Ab Initio Methods for the Calculation of NMR Shielding and Indirect Spinminus signSpin Coupling Constants. Chemical Reviews. 99: 293-352. PMID 11848983 DOI: 10.1021/Cr960017T  0.605
1999 Klopper W, Bak KL, Jørgensen P, Olsen J, Helgaker T. Highly accurate calculations of molecular electronic structure Journal of Physics B: Atomic, Molecular and Optical Physics. 32: R103-R130. DOI: 10.1088/0953-4075/32/13/201  0.427
1999 Bakken V, Helgaker T, Klopper W, Ruud K. The calculation of molecular geometrical properties in the Hellmann—Feynman approximation Molecular Physics. 96: 653-671. DOI: 10.1080/00268979909483002  0.654
1999 Halkier A, Klopper W, Helgaker T, Jo/rgensen P. Basis-set convergence of the molecular electric dipole moment The Journal of Chemical Physics. 111: 4424-4430. DOI: 10.1063/1.480036  0.475
1999 Halkier A, Klopper W, Helgaker T, Jørgensen P, Taylor PR. Basis set convergence of the interaction energy of hydrogen-bonded complexes Journal of Chemical Physics. 111: 9157-9167. DOI: 10.1063/1.479830  0.598
1999 Åstrand P, Ruud K, Mikkelsen KV, Helgaker T. Rovibrationally averaged magnetizability, rotational g factor, and indirect spin–spin coupling of the hydrogen fluoride molecule The Journal of Chemical Physics. 110: 9463-9468. DOI: 10.1063/1.478912  0.608
1999 Dahle P, Ruud K, Helgaker T, Taylor PR. Molecular polarizabilities and magnetizabilities Theoretical and Computational Chemistry. 6: 147-188. DOI: 10.1016/S1380-7323(99)80008-9  0.693
1999 Halkier A, Helgaker T, Jørgensen P, Klopper W, Olsen J. Basis-set convergence of the energy in molecular Hartree–Fock calculations Chemical Physics Letters. 302: 437-446. DOI: 10.1016/S0009-2614(99)00179-7  0.348
1999 Mikkelsen KV, Ruud K, Helgaker T. Solvent effects on the NMR parameters of H2S and HCN Journal of Computational Chemistry. 20: 1281-1291. DOI: 10.1002/(Sici)1096-987X(199909)20:12<1281::Aid-Jcc8>3.0.Co;2-C  0.63
1998 Vaara J, Lounila J, Ruud K, Helgaker T. Rovibrational effects, temperature dependence, and isotope effects on the nuclear shielding tensors of water: A new 17O absolute shielding scale The Journal of Chemical Physics. 109: 8388-8397. DOI: 10.1063/1.477501  0.599
1998 Rizzo A, Ruud K, Helgaker T, Jaszuński M. Electric field gradient, generalized Sternheimer shieldings and electric field gradient polarizabilities by multiconfigurational SCF response The Journal of Chemical Physics. 109: 2264-2274. DOI: 10.1063/1.476794  0.587
1998 Jonsson D, Norman P, Ruud K, Ågren H, Helgaker T. Electric and magnetic properties of fullerenes The Journal of Chemical Physics. 109: 572-577. DOI: 10.1063/1.476593  0.782
1998 Ruud K, Jonsson D, Norman P, Ågren H, Saue T, Jensen HJA, Dahle P, Helgaker T. Generalized integral-screening for efficient calculations of nonlinear optical properties of large molecules The Journal of Chemical Physics. 108: 7973-7979. DOI: 10.1063/1.476237  0.777
1998 Christiansen O, Halkier A, Koch H, Jo/rgensen P, Helgaker T. Integral-direct coupled cluster calculations of frequency-dependent polarizabilities, transition probabilities and excited-state properties The Journal of Chemical Physics. 108: 2801-2816. DOI: 10.1063/1.475671  0.4
1998 Åstrand P, Mikkelsen KV, Jo/rgensen P, Ruud K, Helgaker T. Solvent effects on nuclear shieldings and spin–spin couplings of hydrogen selenide The Journal of Chemical Physics. 108: 2528-2537. DOI: 10.1063/1.475656  0.65
1998 Ruud K, Ågren H, Dahle P, Helgaker T, Rizzo A, Coriani S, Koch H, Sylvester-Hvid KO, Mikkelsen KV. The Cotton–Mouton effect of liquid water. Part II: The semi-continuum model The Journal of Chemical Physics. 108: 599-603. DOI: 10.1063/1.475422  0.646
1998 Åstrand P, Ruud K, Mikkelsen KV, Helgaker T. Atomic Charges of the Water Molecule and the Water Dimer The Journal of Physical Chemistry A. 102: 7686-7691. DOI: 10.1021/Jp980574E  0.562
1998 Ruud K, Vaara J, Lounila J, Helgaker T. Vibrationally averaged magnetizabilities and rotational g tensors of the water molecule Chemical Physics Letters. 297: 467-474. DOI: 10.1016/S0009-2614(98)01155-5  0.596
1998 Halkier A, Helgaker T, Jørgensen P, Klopper W, Koch H, Olsen J, Wilson AK. Basis-set convergence in correlated calculations on Ne, N2, and H2O Chemical Physics Letters. 286: 243-252. DOI: 10.1016/S0009-2614(98)00111-0  0.651
1998 Ruud K, Ågren H, Helgaker T, Dahle P, Koch H, Taylor PR. The Hartree–Fock magnetizability of C60 Chemical Physics Letters. 285: 205-209. DOI: 10.1016/S0009-2614(98)00042-6  0.707
1998 Klopper W, Helgaker T. Extrapolation to the limit of a complete basis set for electronic structure calculations on the N 2 molecule Theoretical Chemistry Accounts: Theory, Computation, and Modeling (Theoretica Chimica Acta). 99: 265-271. DOI: 10.1007/S002140050335  0.47
1998 Helgaker T, Jaszuński M, Ruud K, Górska A. Basis-set dependence of nuclear spin-spin coupling constants Theoretical Chemistry Accounts: Theory, Computation, and Modeling (Theoretica Chimica Acta). 99: 175-182. DOI: 10.1007/S002140050321  0.592
1997 SAUE BT, FAEGRI K, HELGAKER T, GROPEN O. Principles of direct 4-component relativistic SCF: application to caesium auride Molecular Physics. 91: 937-950. DOI: 10.1080/002689797171058  0.344
1997 HELGAKER T, JASZUNSKI M, RUUD K. Ab initio calculation of the NMR shielding and indirect spin-spin coupling constants of fluoroethylene Molecular Physics. 91: 881-889. DOI: 10.1080/00268979709482778  0.58
1997 Ruud K, Helgaker T, Rizzo A, Coriani S, Mikkelsen KV. The Cotton-Mouton effect of liquid water. Part I: The dielectric continuum model The Journal of Chemical Physics. 107: 894-901. DOI: 10.1063/1.474387  0.591
1997 Halkier A, Koch H, Christiansen O, Jo/rgensen P, Helgaker T. First-order one-electron properties in the integral-direct coupled cluster singles and doubles model The Journal of Chemical Physics. 107: 849-866. DOI: 10.1063/1.474384  0.454
1997 Sjo/voll M, Fagerli H, Gropen O, Almlöf J, Saue T, Olsen J, Helgaker T. Extensive relativistic calculations on the palladium hydride molecule The Journal of Chemical Physics. 107: 5496-5501. DOI: 10.1063/1.474254  0.67
1997 Ruud K, Helgaker T, Jo/rgensen P. The effect of correlation on molecular magnetizabilities and rotational g tensors The Journal of Chemical Physics. 107: 10599-10606. DOI: 10.1063/1.474174  0.591
1997 Helgaker T, Klopper W, Koch H, Noga J. Basis-set convergence of correlated calculations on water The Journal of Chemical Physics. 106: 9639-9646. DOI: 10.1063/1.473863  0.457
1997 Helgaker T, Gauss J, Jo/rgensen P, Olsen J. The prediction of molecular equilibrium structures by the standard electronic wave functions The Journal of Chemical Physics. 106: 6430-6440. DOI: 10.1063/1.473634  0.641
1997 Koch H, Christiansen O, Jo/rgensen P, Sanchez de Merás AM, Helgaker T. The CC3 model: An iterative coupled cluster approach including connected triples The Journal of Chemical Physics. 106: 1808-1818. DOI: 10.1063/1.473322  0.398
1997 Mikkelsen KV, Jo/rgensen P, Ruud K, Helgaker T. A multipole reaction-field model for gauge-origin independent magnetic properties of solvated molecules The Journal of Chemical Physics. 106: 1170-1180. DOI: 10.1063/1.473212  0.628
1997 Ruud K, Helgaker T, Uggerud E. Mechanisms, energetics and dynamics of a key reaction sequence during the decomposition of nitromethane: HNO + HNO → N2O + H2O Journal of Molecular Structure: Theochem. 393: 59-71. DOI: 10.1016/S0166-1280(96)04852-X  0.554
1997 Halkier A, Jørgensen P, Gauss J, Helgaker T. CCSDT calculations of molecular equilibrium geometries Chemical Physics Letters. 274: 235-241. DOI: 10.1016/S0009-2614(97)00652-0  0.578
1997 Åstrand P, Ruud K, Mikkelsen KV, Helgaker T. The magnetizability anisotropy and rotational g factor of deuterium hydride and the deuterium molecule Chemical Physics Letters. 271: 163-166. DOI: 10.1016/S0009-2614(97)00429-6  0.586
1997 Ruud K, Helgaker T. The magnetizability, rotational g tensor, and quadrupole moment of PF3 revisited Chemical Physics Letters. 264: 17-23. DOI: 10.1016/S0009-2614(96)01305-X  0.533
1997 Klopper W, Noga J, Koch H, Helgaker T. Multiple basis sets in calculations of triples corrections in coupled-cluster theory Theoretical Chemistry Accounts: Theory, Computation, and Modeling (Theoretica Chimica Acta). 97: 164-176. DOI: 10.1007/S002140050250  0.441
1997 Halkier A, Koch H, Jørgensen P, Christiansen O, Nielsen IMB, Helgaker T. A systematic ab initio study of the water dimer in hierarchies of basis sets and correlation models Theoretical Chemistry Accounts: Theory, Computation, and Modeling (Theoretica Chimica Acta). 97: 150-157. DOI: 10.1007/S002140050248  0.394
1996 CORIANI S, RIZZO A, RUUD K, HELGAKER T. MCSCF calculations of hypermagnetizabilities and nuclear shielding polarizabilities of CO and CH4 Molecular Physics. 88: 931-947. DOI: 10.1080/00268979609484483  0.6
1996 Gauss J, Ruud K, Helgaker T. Perturbation‐dependent atomic orbitals for the calculation of spin‐rotation constants and rotational g tensors The Journal of Chemical Physics. 105: 2804-2812. DOI: 10.1063/1.472143  0.718
1996 Christiansen O, Koch H, Halkier A, Jo/rgensen P, Helgaker T, Sánchez de Merás A. Large‐scale calculations of excitation energies in coupled cluster theory: The singlet excited states of benzene The Journal of Chemical Physics. 105: 6921-6939. DOI: 10.1063/1.471985  0.423
1996 Koch H, Jo/rgensen P, Helgaker T. The molecular structure of ferrocene The Journal of Chemical Physics. 104: 9528-9530. DOI: 10.1063/1.471695  0.391
1996 Koch H, Sánchez de Merás A, Helgaker T, Christiansen O. The integral‐direct coupled cluster singles and doubles model The Journal of Chemical Physics. 104: 4157-4165. DOI: 10.1063/1.471227  0.359
1996 Åstrand P, Mikkelsen KV, Ruud K, Helgaker T. Magnetizabilities and Nuclear Shielding Constants of the Fluoromethanes in the Gas Phase and Solution The Journal of Physical Chemistry. 100: 19771-19782. DOI: 10.1021/Jp961701E  0.588
1996 Bueker H, Helgaker T, Ruud K, Uggerud E. Energetics and Dynamics of Intermolecular Proton-Transfer Processes. 2. Ab Initio Direct Dynamics Calculations of the Reaction H3O++ NH3→ NH4++ H2O The Journal of Physical Chemistry. 100: 15388-15392. DOI: 10.1021/Jp960943B  0.555
1996 Ruud K, åstrand P, Helgaker T, Mikkelsen KV. Full CI calculations of the magnetizability and rotational g factor of the hydrogen molecule Journal of Molecular Structure: Theochem. 388: 231-235. DOI: 10.1016/S0166-1280(96)80036-4  0.523
1996 Christiansen O, Koch H, Jørgensen P, Helgaker T. Integral direct calculation of CC2 excitation energies: singlet excited states of benzene Chemical Physics Letters. 263: 530-539. DOI: 10.1016/S0009-2614(96)01245-6  0.457
1996 Mikkelsen KV, Ruud K, Helgaker T. Magnetizability and nuclear shielding constants of solvated water Chemical Physics Letters. 253: 443-447. DOI: 10.1016/0009-2614(96)00264-3  0.584
1996 Norman P, Jonsson D, Ågren H, Dahle P, Ruud K, Helgaker T, Koch H. Efficient parallel implementation of response theory: Calculations of the second hyperpolarizability of polyacenes Chemical Physics Letters. 253: 1-7. DOI: 10.1016/0009-2614(96)00246-1  0.794
1996 Barszczewicz A, Jaszuński M, Helgaker T, Ruud K. Long-range effects of interatomic interactions on NMR shielding constants Chemical Physics Letters. 250: 1-8. DOI: 10.1016/0009-2614(96)00005-X  0.552
1996 Jaszuński M, Helgaker T, Ruud K. Ab Initio Studies of the [AX]2 Spin Systems ofcis- andtrans-N2F2 Magnetic Resonance in Chemistry. 34: 646-649. DOI: 10.1002/(Sici)1097-458X(199608)34:8<646::Aid-Omr947>3.0.Co;2-5  0.509
1995 Luo Y, gren H, Koch H, Jorgensen P, Helgaker T. Random-phase calculations of frequency-dependent polarizabilities and hyperpolarizabilities of long polyene chains. Physical Review. B, Condensed Matter. 51: 14949-14957. PMID 9978448 DOI: 10.1103/Physrevb.51.14949  0.42
1995 Leere Øiestad E, Leere Øiestad Å, Skaane H, Ruud K, Helgaker T, Uggerud E, Vulpius T. Loss of H2 from CH3NH3+, CH3OH2+ and CH3FH+. Reaction mechanisms and dynamics from observation of metastable ion fragmentations and ab initio calculations European Journal of Mass Spectrometry. 1: 121. DOI: 10.1255/Ejms.145  0.567
1995 Jaszuński M, Helgaker T, Ruud K, Jørgensen P, Bak KL, Koch H. SCF calculations of the NMR shielding tensor for the ethylenic carbon atom in C3Cl4 Molecular Physics. 85: 671-673. DOI: 10.1080/00268979500101381  0.608
1995 Rizzo A, Helgaker T, Ruud K, Barszczewicz A, Jaszuński M, Jo/rgensen P. Electric field dependence of magnetic properties: Multiconfigurational self‐consistent field calculations of hypermagnetizabilities and nuclear shielding polarizabilities of N2, C2H2, HCN, and H2O The Journal of Chemical Physics. 102: 8953-8966. DOI: 10.1063/1.468949  0.596
1995 Ruud K, Helgaker T, Bak KL, Jørgensen P, Olsen J. Accurate magnetizabilities of the isoelectronic series BeH−, BH, and CH+. The MCSCF-GIAO approach Chemical Physics. 195: 157-169. DOI: 10.1016/0301-0104(95)00052-P  0.586
1995 Jaszuński M, Szymański S, Christiansen O, Jørgensen P, Helgaker T, Ruud K. NMR properties of N3−. A comparison of theory and experiment Chemical Physics Letters. 243: 144-150. DOI: 10.1016/0009-2614(95)00806-F  0.597
1995 Ruud K, Helgaker T, Olsen J, Jørgensen P, Bak KL. A numerically stable orbital connection for the calculation of analytical Hessians using perturbation-dependent basis sets Chemical Physics Letters. 235: 47-52. DOI: 10.1016/0009-2614(95)00092-I  0.641
1995 Bak KL, Hansen AE, Ruud K, Helgaker T, Olsen J, Jørgensen P. Ab initio calculation of electronic circular dichroism for trans-cyclooctene using London atomic orbitals Theoretica Chimica Acta. 90: 441-458. DOI: 10.1007/Bf01113546  0.64
1995 Olsen J, Bak KL, Ruud K, Helgaker T, J�rgensen P. Orbital connections for perturbation-dependent basis sets Theoretica Chimica Acta. 90: 421-439. DOI: 10.1007/Bf01113545  0.621
1995 Barszczewicz A, Helgaker T, Jaszunski M, Jorgensen P, Ruud K. NMR Shielding Tensors and Indirect Spin-Spin Coupling Tensors in HCN, HNC, CH3CN, and Ch3NC Molecules Journal of Magnetic Resonance, Series A. 114: 212-218. DOI: 10.1006/Jmra.1995.1128  0.587
1994 Barszczewicz A, Helgaker T, Jaszuński M, Jo/rgensen P, Ruud K. Multiconfigurational self‐consistent field calculations of nuclear magnetic resonance indirect spin–spin coupling constants The Journal of Chemical Physics. 101: 6822-6828. DOI: 10.1063/1.468310  0.63
1994 Hettema H, Wormer PES, Jo/rgensen P, Jensen HJA, Helgaker T. Frequency‐dependent polarizabilities of O2 and van der Waals coefficients of dimers containing O2 The Journal of Chemical Physics. 100: 1297-1302. DOI: 10.1063/1.467256  0.352
1994 Bak KL, Jo/rgensen P, Helgaker T, Ruud K, Jo/rgen Aa. Jensen H. Basis set convergence of atomic axial tensors obtained from self‐consistent field calculations using London atomic orbitals The Journal of Chemical Physics. 100: 6620-6627. DOI: 10.1063/1.467019  0.623
1994 Ruud K, Helgaker T, Kobayashi R, Jo/rgensen P, Bak KL, Jensen HJA. Multiconfigurational self‐consistent field calculations of nuclear shieldings using London atomic orbitals The Journal of Chemical Physics. 100: 8178-8185. DOI: 10.1063/1.466812  0.637
1994 Helgaker T, Ruud K, Bak KL, Jørgensen P, Olsen J. Vibrational Raman optical activity calculations using London atomic orbitals Faraday Discuss.. 99: 165-180. DOI: 10.1039/Fd9949900165  0.656
1994 Bak KL, Jørgensen P, Helgaker T, Ruud K. Basis set convergence and correlation effects in vibrational circular dichroism calculations using London atomic orbitals Faraday Discuss.. 99: 121-129. DOI: 10.1039/Fd9949900121  0.622
1994 Ruud K, Skaane H, Helgaker T, Bak KL, Joergensen P. Magnetizability of Hydrocarbons Journal of the American Chemical Society. 116: 10135-10140. DOI: 10.1021/Ja00101A036  0.455
1994 Olsen J, Minaev B, Vahtras O, Ågren H, Jørgensen P, Jensen HJA, Helgaker T. The Vegard-Kaplan band and the phosphorescent decay of N2 Chemical Physics Letters. 231: 387-394. DOI: 10.1016/0009-2614(94)01300-4  0.494
1994 Koch H, Christiansen O, Kobayashi R, Jørgensen P, Helgaker T. A direct atomic orbital driven implementation of the coupled cluster singles and doubles (CCSD) model Chemical Physics Letters. 228: 233-238. DOI: 10.1016/0009-2614(94)00898-1  0.374
1994 Ruud K, Helgaker T, Jørgensen P, Bak KL. Theoretical calculations of the magnetizability of some small fluorine-containing molecules using London atomic orbitals Chemical Physics Letters. 223: 12-18. DOI: 10.1016/0009-2614(94)00407-2  0.624
1994 Jaszunski M, Jørgensen P, Rizzo A, Ruud K, Helgaker T. MCSCF calculations of Verdet constants Chemical Physics Letters. 222: 263-266. DOI: 10.1016/0009-2614(94)00350-5  0.632
1994 Jaszunski M, Helgaker T, Ruud K, Bak KL, Jørgensen P. MCSCF calculations of nitrogen NMR shielding constants using London atomic orbitals Chemical Physics Letters. 220: 154-160. DOI: 10.1016/0009-2614(94)00163-4  0.624
1994 Ischtwan J, Schwerdtfeger P, Peyerimhoff SD, Collins MA, Helgaker T, J�rgensen P, Jensen HJA. MCSCF reaction-path energetics and thermal rate-constants for the reaction of3NH with H2 Theoretica Chimica Acta. 89: 157-168. DOI: 10.1007/Bf01132799  0.332
1993 Ruud K, Helgaker T, Bak KL, Jo/rgensen P, Jensen HJA. Hartree–Fock limit magnetizabilities from London orbitals The Journal of Chemical Physics. 99: 3847-3859. DOI: 10.1063/1.466131  0.613
1993 Ågren H, Vahtras O, Koch H, Jo/rgensen P, Helgaker T. Direct atomic orbital based self‐consistent‐field calculations of nonlinear molecular properties. Application to the frequency dependent hyperpolarizability of para‐nitroaniline The Journal of Chemical Physics. 98: 6417-6423. DOI: 10.1063/1.465099  0.526
1993 Jaszuński M, Jo/rgensen P, Koch H, Ågren H, Helgaker T. Frequency dependent hyperpolarizabilities of polyynes The Journal of Chemical Physics. 98: 7229-7235. DOI: 10.1063/1.464714  0.481
1993 Bak KL, Jo/rgensen P, Helgaker T, Ruud K, Jensen HJA. Gauge‐origin independent multiconfigurational self‐consistent‐field theory for vibrational circular dichroism The Journal of Chemical Physics. 98: 8873-8887. DOI: 10.1063/1.464445  0.633
1993 Koch H, Ågren H, Jørgensen P, Helgaker T, Jensen HJA. Large scale random phase calculations for direct self-consistent field wavefunctions Chemical Physics. 172: 13-20. DOI: 10.1016/0301-0104(93)80102-F  0.369
1993 Jaszunski M, Bak KL, Jørgensen P, Helgaker T, Ruud K, Jørgen H, Jensen A. Nuclear magnetic shielding tensor for the ethylenic carbon atom in tetrachlorocyclopropene Chemical Physics Letters. 204: 608-610. DOI: 10.1016/0009-2614(93)89212-Z  0.589
1993 Vahtras O, Ågren H, Jørgensen P, Helgaker T, Jensen H. The nuclear spin—spin coupling in N2 and CO Chemical Physics Letters. 209: 201-206. DOI: 10.1016/0009-2614(93)80093-5  0.536
1993 Barszczewicz A, Jaszuński M, Kamieńska-Trela K, Helgaker T, Jørgensen P, Vahtras O. Ab initio study of the NMR shielding constants and spin-spin coupling constants in cyclopropene Theoretica Chimica Acta. 87: 19-28. DOI: 10.1007/Bf01113526  0.426
1993 Bråten SM, Helgaker T, Uggerud E, Vulpius T. Mechanism, energetics, kinetics and dynamics of the reaction C2H6+˙ → C2H4+˙ + H2 Organic Mass Spectrometry. 28: 1262-1269. DOI: 10.1002/Oms.1210281043  0.312
1992 Helgaker T, Tomashevsky I. The hydrogen atom in crossed static electromagnetic and non-resonant laser fields Physica Scripta. 46: 354-356. DOI: 10.1088/0031-8949/46/4/007  0.408
1992 Bak KL, Jo/rgensen P, Jensen HJA, Olsen J, Helgaker T. First‐order nonadiabatic coupling matrix elements from multiconfigurational self‐consistent‐field response theory The Journal of Chemical Physics. 97: 7573-7584. DOI: 10.1063/1.463477  0.389
1992 Vahtras O, Ågren H, Jo/rgensen P, Jensen HJA, Helgaker T, Olsen J. Multiconfigurational quadratic response functions for singlet and triplet perturbations: The phosphorescence lifetime of formaldehyde The Journal of Chemical Physics. 97: 9178-9187. DOI: 10.1063/1.463344  0.532
1992 Stanton JF, Gauss J, Bartlett RJ, Helgaker T, Jo/rgensen P, Jensen HJA, Taylor PR. Interconversion of diborane (4) isomers The Journal of Chemical Physics. 97: 1211-1216. DOI: 10.1063/1.463247  0.691
1992 Fernandez B, Jo/rgensen P, Byberg J, Olsen J, Helgaker T, Jensen HJA. Spin polarization in restricted electronic structure theory: Multiconfiguration self‐consistent‐field calculations of hyperfine coupling constants The Journal of Chemical Physics. 97: 3412-3419. DOI: 10.1063/1.462977  0.412
1992 Vahtras O, Ågren H, Jo/rgensen P, Jo/rgen Aa. Jensen H, Padkjær SB, Helgaker T. Indirect nuclear spin–spin coupling constants from multiconfiguration linear response theory The Journal of Chemical Physics. 96: 6120-6125. DOI: 10.1063/1.462654  0.559
1992 Vahtras O, Ågren H, Jo/rgensen P, Jo/rgen Aa. Jensen H, Helgaker T, Olsen J. Spin–orbit coupling constants in a multiconfiguration linear response approach The Journal of Chemical Physics. 96: 2118-2126. DOI: 10.1063/1.462063  0.504
1992 Uggerud E, Helgaker T. Dynamics of the reaction CH2OH+ .fwdarw. CHO+ + H2. Translational energy release from ab initio trajectory calculations Journal of the American Chemical Society. 114: 4265-4268. DOI: 10.1021/Ja00037A033  0.36
1992 Jaszuński M, Jensen HJA, Jørgensen P, Rizzo A, Helgaker T, Ruud K. The magnetic hyperpolarizability anisotropy of the neon atom Chemical Physics Letters. 191: 599-602. DOI: 10.1016/0009-2614(92)85595-2  0.585
1992 Helgaker T, Taylor PR. On the evaluation of derivatives of Gaussian integrals Theoretica Chimica Acta. 83: 177-183. DOI: 10.1007/Bf01132826  0.492
1992 Vahtras O, Ågren H, Jørgensen P, Jørgen H, Jensen A, Helgaker T. The second-order energy contribution from the spin-orbit interaction operator to the potential energy curve of Cr2 International Journal of Quantum Chemistry. 41: 729-731. DOI: 10.1002/Qua.560410509  0.528
1991 Cesar A, Ågren H, Helgaker T, Jo/rgensen P, Jensen HJA. Excited state structures and vibronic spectra of H2CO+, HDCO+, and D2CO+ using molecular gradient and Hessian techniques The Journal of Chemical Physics. 95: 5906-5917. DOI: 10.1063/1.461612  0.51
1991 Helgaker T, Jo/rgensen P. An electronic Hamiltonian for origin independent calculations of magnetic properties The Journal of Chemical Physics. 95: 2595-2601. DOI: 10.1063/1.460912  0.477
1991 Špirko V, Daadoch NM, Jensen HJA, J∅rgensen P, Helgaker T. An ab initio investigation of the potential energy function and rotation—vibration energies of H2O·Na+ Chemical Physics Letters. 185: 265-269. DOI: 10.1016/S0009-2614(91)85058-5  0.381
1990 Koch H, Jensen HJA, Jo/rgensen P, Helgaker T. Excitation energies from the coupled cluster singles and doubles linear response function (CCSDLR). Applications to Be, CH+, CO, and H2O The Journal of Chemical Physics. 93: 3345-3350. DOI: 10.1063/1.458815  0.385
1990 Koch H, Jensen HJA, Jo/rgensen P, Helgaker T, Scuseria GE, Schaefer HF. Coupled cluster energy derivatives. Analytic Hessian for the closed‐shell coupled cluster singles and doubles wave function: Theory and applications The Journal of Chemical Physics. 92: 4924-4940. DOI: 10.1063/1.457710  0.414
1990 Helgaker T, Uggerud E, Jensen HJA. Integration of the classical equations of motion on ab initio molecular potential energy surfaces using gradients and Hessians: application to translational energy release upon fragmentation Chemical Physics Letters. 173: 145-150. DOI: 10.1016/0009-2614(90)80068-O  0.38
1989 Jensen HJA, Jørgensen P, Helgaker T, Olsen J. Accurate calculations of the dynamic dipole polarizability of N2. A multiconfigurational linear response study using restricted active space (RAS) wavefunctions Chemical Physics Letters. 162: 355-360. DOI: 10.1016/0009-2614(89)87058-7  0.366
1989 Helgaker T, Jørgensen P, Handy NC. A numerically stable procedure for calculating Møller-Plesset energy derivatives, derived using the theory of Lagrangians Theoretica Chimica Acta. 76: 227-245. DOI: 10.1007/Bf00532006  0.587
1989 Helgaker T, J�rgensen P. Configuration-interaction energy derivatives in a fully variational formulation Theoretica Chimica Acta. 75: 111-127. DOI: 10.1007/Bf00527713  0.37
1988 Helgaker T, Ewbank JD. Translational and rotational symmetries of molecular geometrical derivatives Acta Chemica Scandinavica. 42: 515-518. DOI: 10.3891/Acta.Chem.Scand.42A-0515  0.309
1988 Helgaker T, Almlöf J. Molecular wave functions and properties calculated using floating Gaussian orbitals The Journal of Chemical Physics. 89: 4889-4902. DOI: 10.1063/1.455659  0.678
1988 Jo/rgensen P, Helgaker T. Mo/ller–Plesset energy derivatives The Journal of Chemical Physics. 89: 1560-1570. DOI: 10.1063/1.455152  0.372
1988 Mikkelsen KV, Ågren H, Jensen HJA, Helgaker T. A multiconfigurational self‐consistent reaction‐field method The Journal of Chemical Physics. 89: 3086-3095. DOI: 10.1063/1.454965  0.533
1988 Almlof J, Helgaker T, Taylor PR. Gaussian basis sets for high-quality ab initio calculations The Journal of Physical Chemistry. 92: 3029-3033. DOI: 10.1021/J100322A003  0.707
1988 Helgaker T, Jørgensen P. Analytical Calculation of Geometrical Derivatives in Molecular Electronic Structure Theory Advances in Quantum Chemistry. 19: 183-245. DOI: 10.1016/S0065-3276(08)60616-4  0.47
1988 J�rgensen P, Jensen HJA, Helgaker T. A gradient extremal walking algorithm Theoretica Chimica Acta. 73: 55-65. DOI: 10.1007/Bf00526650  0.332
1986 Jensen HJA, Jo/rgensen P, Helgaker T. Systematic determination of MCSCF equilibrium and transition structures and reaction paths The Journal of Chemical Physics. 85: 3917-3929. DOI: 10.1063/1.450914  0.407
1984 Helgaker TU, Almlöf J. A second-quantization approach to the analytical evaluation of response properties for perturbation-dependent basis sets International Journal of Quantum Chemistry. 26: 275-291. DOI: 10.1002/Qua.560260211  0.624
1982 Almenningen A, Helgaker T, Haaland A, Samdal S. The molecular structures of dimethyl-, diethyl- and dipropylzinc determined by gas phase electron diffraction. Normal coordinate analysis and ab initio molecular orbital calculations on dimethylzinc Acta Chemica Scandinavica. 159-166. DOI: 10.3891/Acta.Chem.Scand.36A-0159  0.394
1981 Almlöf J, Helgaker T. Basis set considerations for the calculation of gradients in the lcao formalism Chemical Physics Letters. 83: 125-128. DOI: 10.1016/0009-2614(81)80303-X  0.65
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