Nonadiabatic perturbations and fine structure splittings in the 1,2 [sup 3][Pi][sub [ital g]] states of B[sub 2]: An analysis based on adiabatic and rigorous diabatic states
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218 (United States)
Nonadiabatic effects and fine structure splittings in the 1,2 [sup 3][Pi][sub [ital g]] states of B[sub 2] were studied. Adiabatic electronic wave functions [Psi][sup [ital a]]([ital J] [sup 3][Pi][sub [ital g]]) were computed at the multireference configuration interaction level. The interstate derivative couplings [l angle][Psi][sup [ital a]](1 [sup 3][Pi][sub [ital g]])[vert bar]([ital d]/[ital dR])[Psi][sup [ital a]](2 [sup 3][Pi][sub [ital g]])[r angle] were computed and used to construct rigorous'' diabatic electronic states. The spin--orbit interactions responsible for the fine structure splitting in the 1,2 [sup 3][Pi][sub [ital g]] states were determined, as were the 1,2 [sup 3][Pi][sub [ital g]][similar to]1 [sup 1][Pi][sub [ital g]] spin--orbit interactions. These electronic structure data were used to determine the vibrational structure of the 1,2 [sup 3][Pi][sub [ital g]] states in both coupled adiabatic and coupled diabatic states bases. As a result of an avoided crossing of the 1,2 [sup 3][Pi][sub [ital g]] states the fine structure splitting constants exhibit a marked geometry dependence. The fine structure splitting constants for the (1 [sup 3][Pi][sub [ital g]], [ital v]=0--4) levels were found to be [minus]4.2([minus]4.4), [minus]3.7, [minus]2.8, [minus]1.8, and [minus]0.83 cm[sup [minus]1], respectively. The (1 [sup 3][Pi][sub [ital g]], [ital v]=0) value is in good agreement with a recent experimental determination given parenthetically. While the diabatic basis provides illuminating qualitative insights into the electronic structure of the states in question the adiabatic basis is preferred computationally.
- DOE Contract Number:
- FG02-91ER14189
- OSTI ID:
- 7270786
- Journal Information:
- Journal of Chemical Physics; (United States), Vol. 100:11; ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BORON
FINE STRUCTURE
ADIABATIC APPROXIMATION
CONFIGURATION INTERACTION
COUPLING
DIABATIC APPROXIMATION
DIMERS
ELECTRONIC STRUCTURE
L-S COUPLING
VIBRATIONAL STATES
WAVE FUNCTIONS
ELEMENTS
ENERGY LEVELS
EXCITED STATES
FUNCTIONS
INTERMEDIATE COUPLING
SEMIMETALS
664200* - Spectra of Atoms & Molecules & their Interactions with Photons- (1992-)