ISSN:
0020-7608
Keywords:
Symmetry
;
projection operator
;
VB wave function
;
transition energy
;
chemical bonds
;
Chemistry
;
Theoretical, Physical and Computational Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A method constructing symmetry-adapted bonded Young tableau bases is proposed, based on the symmetry properties of bonded tableaus and the projection operator associated with a point group. Several examples including the ground states and π excited states of O3-, O3, O3+, and C3- are shown for instruction to construct the symmetrized valence bond (VB) wave function. Excitation energies of transitions from the ground states to π excited states of O3-, C3H5, and C3- are calculated with an optimized symmetrized valence bond wave function in the σ-π separation approximation. Good agreement between the VB and experimental excitation energies is observed. The bonding features of the ground state and the first π excited singlet and triplet states for S3 are discussed according to bonding populations from VB calculations. Both the singlet-biradical and the dipole structures have significant contributions to the ground state X 1A1 of S3, while the excited state 1 1B2 is essentially composed of the dipole structures, and the 1 3B2 excited state is comprised from a triplet-biradical structure. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 66: 1-7, 1998
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
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