Determination of excitation energies and transition moments in a second order polarization propagator approach. Application to the Be atom and the CH+ molecule

✍ Scribed by Jens Oddershede; Poul Jørgensen; Nelson H. F. Beebe

• Publisher: John Wiley and Sons
• Year: 1977
• Tongue: English
• Weight: 684 KB
• Volume: 12
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/qua.560120406

✦ Synopsis

Abstract

Excitation energies and transition moments have been determined from a second order polarization propagator and the effect of including energy shifted denominators has been investigated. Results for Be and CH^+^ show a change of 2–5% for the transition moments and of 0–20% for the singlet excitation energies in a second order approach compared to a first order (time‐dependent Hartree‐Fock) approximation. Both Be and CH^+^ are triplet unstable in the time‐dependent Hartree‐Fock approximation. The triplet instability is removed for Be but not for CH^+^ in a second order polarization propagator approach.