Unified large basis set diatomics-in-molecules models for ground and excited states of H/sub 3/
A recently developed systematic diatomics-in-molecules (DIM) procedure has been applied to the system H+H/sub 2/ in order to generate large basis set models capable of approximating both the ground and low-lying excited state potential energy surfaces in a unified manner. The procedure, based exclusively on an analysis of diatomic ab initio wave functions, suggests that a 20-structure model including structures with not more than one excited H atom (2s or 2p) should suffice for the H/sub 3/ (/sup 2/A') states. An 80-structure model including up to two excited H atoms yielded potential energy surfaces in close agreement with the smaller model. The ground state surface shows a greatly improved behavior in D/sub 3h/ configurations when compared to the simplest, two-structure DIM model for H/sub 3/ but is otherwise very similar to that surface. This result exemplifies the stability of our systematic DIM methodology to increases in the size of the basis set. A number of excited state surfaces, including the lower /sup 2/A'' and quartet states, are reported and the implications for reaction kinetics are discussed. In particular, we predict the reaction H*(2s or 2p)+H/sub 2/..-->..H+H+H to have a large cross section.
- Research Organization:
- Hahn-Meitner-Institut fuer Kernforschung Berlin GmbH, Glienicker Str. 100, D-1000 Berlin 39, West Germany
- OSTI ID:
- 6337051
- Journal Information:
- J. Chem. Phys.; (United States), Vol. 84:2
- Country of Publication:
- United States
- Language:
- English
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