General method for removing resonance singularities in quantum mechanical perturbation theory

Autor:	Donald G. Truhlar, Alan D. Isaacson, Kathleen M. Kuhler
Rok vydání:	1996
Předmět:	General method Chemistry General Physics and Astronomy Resonance Order (ring theory) Quantum chemistry Classical mechanics Molecular vibration Quantum mechanics Gravitational singularity Physics::Chemical Physics Physical and Theoretical Chemistry Perturbation theory Quantum
Zdroj:	The Journal of Chemical Physics. 104:4664-4671
ISSN:	1089-7690 0021-9606
Popis:	This paper presents a way of improving second‐order perturbation theory calculations by summing contributions of uncoupled excitations to infinite order. For problems involving molecular vibrations, the new theory is shown to give similar results to conventional second‐order perturbation theory when the system treated has no near resonances but also to give accurate and stable results even very close to resonance. The new theory is tested by comparison to converged variational calculations for vibrational energy levels of formaldehyde, formaldehyde‐d2, and two two‐dimensional model subsystems based on formaldehyde.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::f839ea8f82ebe63250bb9fecb738ae21 https://doi.org/10.1063/1.471161 Zobrazit plný text záznamu