A technique for embedding clusters in ionic crystals using the Gaussian 92 quantum chemical program
- Optex Communicaitons Corporation, Rockville, MD (United States)
- Oklahoma State Univ., Stillwater, OK (United States)
We present a technique for embedding clusters of atoms, which are to be treated quantum mechanically, in ionic crystals by representing the external lattice by classical lattice-centered Gaussian charge distributions. The goal is to carry out ab initio self-consistent field calculations of the many-electron ground and excited states of finite clusters representing defects in an otherwise perfect crystal lattice. We describe a procedure for determining the effective charges and Gaussian exponents describing the external lattice so that, together with Hartree-Fock force calculations, the net forces an the quantum mechanical cluster ions are zero in the ground state. The result of this procedure is the production of an external coulombic field that has the same symmetry as the crystal, exactly balances the quantum mechanical forces, and simultaneously accounts for the fact that the external charge distribution is finite. The method is illustrated by considering the formation of the F-center defect in CaF{sub 2}. 17 refs., 5 figs., 2 tabs.
- OSTI ID:
- 478609
- Journal Information:
- Journal of Computational Physics, Vol. 129, Issue 1; Other Information: PBD: Nov 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
(Theory of defects in non-metallic solids): Progress report, 1 August 1985-1 May 1988
Ab initio cluster study of crystalline NaF