Calculations of the optical properties for FA1:Ag+ centers and CN interactions at the regular and defect sites of the LiI (0 0 1) surface: First principle calculations

The optical properties of the FA1:Ag+ color centers and CN interactions at the flat, edge and corner surfaces of LiI (0 0 1) were investigated by using quantum mechanical configuration interaction singles (CIS) and density functional theory (DFT) ab initio methods. Clusters of variable sizes were embedded in the simulated Coulomb fields that closely approximate the Madelung fields of the host surfaces, and the nearest-neighbor ions to the defect site were allowed to relax to equilibrium in order to calculate the optical properties. The sensitivity of the calculated transition energies (Stokes shifts) of FA1:Ag+ centers as well as related optical properties such as optical–optical conversion efficiency, relaxed excited states of the defect-containing surface, orientational destruction of the point defect, recording sensitivity, and the Glasner–Tompkins empirical rule, to the coordination number of the surface ion and artificial polarization were examined. The dependance of the adsorption energies of CN at LiI (0 0 1) surface, the coadsorption of CN, and the charge transfer reactions between CN and the paramagnetic iodine vacancy on the coordination number and artificial polarization effects were also clarified.