title: Calculation of frequency-dependent hyperpolarizabilities using general coupled-cluster models.
abstract: By exploiting the similarities between response theory and analytic derivative theory, we present a scheme for calculating frequency-dependent hyperpolarizabilities at the coupled-cluster level within the framework for analytic third derivatives. This has been implemented for arbitrary levels of coupled-cluster theory up to the full-configuration-interaction limit. An investigation of some small molecules shows that the inclusion of triple excitations is essential for an accurate description of hyperpolarizabilities.
authors.affiliation: Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz, Germany. oneill@uni-mainz.de
authors.forename: Darragh P
authors.initials: DP
authors.lastname: O'Neill
authors.forename: Mihály
authors.initials: M
authors.lastname: Kállay
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gauss