Modeling of high-order terms in potential energy surface expansions using the reference-geometry Harris-Foulkes method

Patrick Meier, Greg Bellchambers, Julian Klepp, Frederick R. Manby, Guntram Rauhut*

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

8 Citations (Scopus)

Abstract

The reference-geometry Harris-Foulkes (RGHF) approach has been used to model high-order terms within the expansion of multi-dimensional potential energy surfaces (PES) as needed within the calculation of accurate vibrational frequencies beyond the harmonic approximation. The key step of this method is a localization of the electron density to the atoms of the molecule at a given reference structure and a subsequent transfer of these atom-centered partial densities to the atom positions of distorted structures. This concept has been used to evaluate the 3-mode coupling terms of a multi-mode expansion of the PES as arising in the Watson Hamiltonian. Systematic benchmark calculations for vibrational frequencies obtained from vibrational configuration interaction (VCI) theory have been performed in order to study the effects of this approximation on the fundamental modes of a test suite of 28 molecules.

Original languageEnglish
Pages (from-to)10233-10240
Number of pages8
JournalPhysical Chemistry Chemical Physics
Volume15
Issue number25
DOIs
Publication statusPublished - 2013

Keywords

  • STATES
  • SYSTEMS
  • POLYATOMIC-MOLECULES
  • VIBRATIONAL WAVE-FUNCTIONS
  • EFFICIENT CALCULATION
  • PLESSET PERTURBATION-THEORY
  • FRAGMENTS
  • INFRARED-SPECTRA
  • AB-INITIO CALCULATIONS
  • SELF-CONSISTENT-FIELD

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