The size of the cations (either Ca2+, Sr2+, Ga+, or
Au+) at the FA1-type color centers on the (100) surface of
LiCl crystal plays an important role in the optical properties
of this surface. In this work, double-well potentials at this
surface were investigated using ab initio quantum mechanical
methods. Quantum clusters were embedded in simulated
Coulomb fields that closely approximate the
Madelung fields of the host surface, and the ions that were
the nearest neighbors to the FA1 site were allowed to relax
to equilibrium. The calculated Stokes-shifted optical transition
bands, optical–optical conversion efficiency, and
relaxed excited states of the defect-containing surface, as
well as the orientational destruction of the color centers,
recording sensitivity, exciton (energy) transfer, and the
Glasner–Tompkins empirical relation were all found to be
sensitive to the size of the dopant cation.