ISSN:
0020-7608
Keywords:
Computational Chemistry and Molecular Modeling
;
Atomic, Molecular and Optical Physics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
MCSCF calculations were performed on the two lowest states of the Li—H2 system, using a basis set of double-zeta-plus-polarization quality. The characters of the wave functions in the region of the conical intersection of the potential energy surfaces were investigated in some detail. The depth of the minimum on the Ã2B2 surface was estimated to be 0.46 eV. The frequency of the a1 vibration at the center of the conical intersection was 3.76 X 1013 sec-1. Under the symmetry of the nuclear geometry lower than C2v in the immediate neighborhood of the center of the intersection, the upper state was characterized by a 3a′ natural orbital by which the more distant H is bonded to Li, while in the lower state the nearer H is bonded to Li. Thus, the process of the nonadiabatic transition caused by a nuclear motion of b2 symmetry is visualized as a smooth bond-preserving process, and is expected to occur with high probability. For the correct description of the states in this region, MCSCF functions comprising limited CSF's were inadequate, and an additional process of nonorthogonal CI was required.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/qua.560290411
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