A hybrid variational-perturbational nuclear motion algorithm

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

A hybrid variational-perturbational nuclear motion algorithm based on the perturbative treatment of the Coriolis coupling terms of the Eckart-Watson kinetic energy operator following a variational treatment of the rest of the operator is described. The algorithm has been implemented in the quantum chemical code DEWE. Performance of the hybrid treatment is assessed by comparing selected numerically exact variational vibration-only and rovibrational energy levels of the C2H4, C2D4, and CH4 molecules with their perturbatively corrected counterparts. For many of the rotational-vibrational states examined, numerical tests reveal excellent agreement between the variational and even the first-order perturbative energy levels, whilst the perturbative approach is able to reduce the computational cost of the matrix-vector product evaluations, needed by the iterative Lanczos eigensolver, by almost an order of magnitude.

Original languageEnglish
Pages (from-to)2462-2467
Number of pages6
JournalMolecular Physics
Volume112
Issue number18
DOIs
Publication statusPublished - Sep 1 2014

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Electron energy levels
Vibration
energy levels
Kinetic energy
Mathematical operators
operators
Costs and Cost Analysis
vibrational states
Molecules
kinetic energy
costs
Costs
vibration
evaluation
products
molecules

Keywords

  • CD
  • CH
  • CH
  • Eckart-Watson Hamiltonian
  • nuclear motion theory
  • variational-perturbational approach

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Condensed Matter Physics
  • Biophysics
  • Molecular Biology

Cite this

A hybrid variational-perturbational nuclear motion algorithm. / Fábri, Csaba; Furtenbacher, T.; Császár, A.

In: Molecular Physics, Vol. 112, No. 18, 01.09.2014, p. 2462-2467.

Research output: Contribution to journalArticle

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