[ital Ab] [ital initio] characterization of electronically excited states in highly unsaturated hydrocarbons

Journal Article · Sun Jan 01 04:00:00 EST 1995 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.469414· OSTI ID:6693156

Sobolewski, A L; Adamowicz, L ^[1]

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1. Department of Chemistry, University of Arizona, Tucson, Arizona 85721 (United States)

The results of extensive electronic structure calculations performed for a series of molecules: (CC)[sub [ital n]]H, H(CC)[sub [ital n]]H[sup +] for [ital n]=2,3,4 and for (CC)[sub 3]H[sup [minus]] and H(CC)[sub 3]H[sup [minus]] are presented. The theoretical scheme is based on the complete-active-space self-consistent-field (CASSCF) method, with remaining dynamic electron correlation effects added in the subsequent step with the use of the second-order perturbation theory with the CASSCF wave function as the reference state (CASPT2). The results support the hypothesis of Fulara [ital et] [ital al]. [Nature [bold 336], 439 (1993)] that the [sup 2][Pi][r arrow][sup 2][Pi] electronic transitions in the series of C[sub [ital n]]H radicals might be responsible for some of the diffuse interstellar bands'' observed in the visible and near-infrared spectra of stars located on the far side of diffuse interstellar clouds.

• DOE Contract Number: FG03-93ER61605
• OSTI ID: 6693156
• Journal Information: Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 102:1; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

664100* -- Theory of Electronic Structure of Atoms & Molecules-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
CORRELATIONS
ELECTRON CORRELATION
ELECTRONIC STRUCTURE
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITED STATES
HYDROCARBONS
INFRARED SPECTRA
INTERSTELLAR SPACE
ORGANIC COMPOUNDS
PERTURBATION THEORY
RADICALS
SATURATION
SPACE
SPECTRA
STARS
VISIBLE SPECTRA