Abstract
An attempt has been made to apply the Glasner-Tompkins relation to LiH and LiF crystals and to examine the reorientation of H and H-2 intersitials in LiF crystal using the matrix Hartree-Fock method of ab initio theory. A finite lattice, in which the Coulomb potential in the central region closely approximates the Made-lung potential in the unit, cell of the host crystal, is constructed. The results emphasize the strong dependence of the difference between the exciton band and the F-center band on the halide species and suggest a mechanism by which the U band bleaches in LiF crystal. The energetically preferred orientation of H-2 interstitials in the < 110 > plane supports the conclusion that the mobile H-2 molecules, while being unable to react with isolated F centers, can react with F-center pairs (M centers) to produce the complex U centers.