A comparison of density-functional-theory and coupled-cluster frequency-dependent polarizabilities and hyperpolarizabilities |
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| Authors: | Pawe? Sa?ek ? Trygve Helgaker Olav Vahtras Hans ?gren Dan Jonsson ⊥ Jürgen Gauss |
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| Institution: | 1. Department of Chemistry , University of Oslo , P.O. Box 1033 Blindern, N-0315 Oslo, Norway;2. Laboratory of Theoretical Chemistry , The Royal Institute of Technology , SE-10044 Stockholm, Sweden;3. Institut für Physikalische Chemie , Universit?t Mainz , D-55099 Mainz, Germany |
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| Abstract: | The frequency-dependent polarizabilities and hyperpolarizabilities of HF, CO, H2O and para-nitroaniline calculated by density-functional theory are compared with accurate coupled-cluster results. Whereas the local-density approximation and the generalized gradient approximation (BLYP) perform very similarly and overestimate polarizabilities and, in particular, the hyperpolarizabilities, hybrid density-functional theory (B3LYP) performs better and produces results similar to those obtained by coupled-cluster singles-and-doubles theory. Comparisons are also made for singlet excitation energies, calculated using linear response theory. |
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