An efficient combination of computational techniques for investigating electronic resonance states in molecules

Citation
R. Santra et Ls. Cederbaum, An efficient combination of computational techniques for investigating electronic resonance states in molecules, J CHEM PHYS, 115(15), 2001, pp. 6853-6861
Citations number
73
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF CHEMICAL PHYSICS
ISSN journal
0021-9606 → ACNP
Volume
115
Issue
15
Year of publication
2001
Pages
6853 - 6861
Database
ISI
SICI code
0021-9606(20011015)115:15<6853:AECOCT>2.0.ZU;2-O
Abstract
Calculating electronic resonance states in molecules is a serious challenge to theory, because the treatment of both the scattering and the many-elect ron problem is a formidable task. A very promising approach, known as CAP/C I, consists of the combination of a complex absorbing potential with the me thod of configuration interaction. In this paper we propose the combination of three distinct computational techniques in order to boost the performan ce of CAP/CI. A complex absorbing potential that can be adjusted flexibly t o the geometry of the molecular scattering target is presented and its repr esentation in a Gaussian basis set is discussed. To handle the large-scale complex symmetric eigenvalue problem arising in CAP/CI, a subspace projecti on method is employed and its validity is shown. We advocate the use of par allel filter diagonalization for calculating the eigenvectors required in t he projection step. The proposed techniques are applied to determine the li fetime of an autoionizing, inner-valence excited state of Ne-2(+). (C) 2001 American Institute of Physics.