title: Calculation of vibrational frequencies through a variational reduced-coupling approach.
abstract: In this study, we present a new method to perform accurate and efficient vibrational configuration interaction computations for large molecular systems. We use the vibrational self-consistent field (VSCF) method to compute an initial description of the vibrational wave function of the system, combined with the single-to-all approach to compute a sparse potential energy surface at the chosen ab initio level of theory. A Davidson scheme is then used to diagonalize the Hamiltonian matrix built on the VSCF virtual basis. Our method is applied to the computation of the OH-stretch frequency of formic acid and benzoic acid to demonstrate the efficiency and accuracy of this new technique.
authors.affiliation: Nachwuchsgruppe Theorie-SFB 569, Albert-Einstein-Allee 11, University of Ulm, D-89081 Ulm, Germany. yohann.scribano@uni-ulm.de
authors.forename: Yohann
authors.initials: Y
authors.lastname: Scribano
authors.forename: David M
authors.initials: DM
authors.lastname: Benoit