Pseudopotential calculation ofF-center spin densities in KCl, NaCl, and NaF

In this paper we give the details of a simple calculational model used recently to interpret the experimental pressure shifts of the $F$-center hyperfine interaction constants in KCl, and report further results on the $F$-center ground-state energies and wave functions for KCl, NaCl, and NaF. The model is based on the pseudopotential approach of Bartram, Stoneham, and Gash, but is modified for consistency with a variational solution and expanded to include contributions from ionic $p$ states. Polarization is included by means of an $r$-dependent polarization potential suggested by Fowler and used in the extensive calculations of Öpik and Wood. Ground-state energies calculated from the model are shown to be comparable in accuracy with those resulting from a more rigorous calculation. Spin densities are reported for the first six shells of KCl, NaCl, and NaF, and good agreement with experiment is obtained in nearly all cases.