An ab-initio Hartree-Fock perturbed-cluster study of neutral defects in LiF

An ab initio Hartree-Fock perturbed-cluster embedding scheme is applied to the problem of neutral defects in bulk LiF (specifically to Na substitutionals and the bound Schottky pair), using an extended basis set. The authors highlight the capabilities and drawbacks of the method, in particular regarding the convergence of the procedure and the description of polarization and relaxation effects. They also compare the results with simulations based on the Mott-Littleton theory. The results indicate that even in the case of neutral defects, there are important short-range polarization effects.