Bond-orbital calculations of the non-linear optical response of lithium niobate-related compounds

Abstract
Second-order non-linear optical tensor coefficients of LiNbO3-type compounds have been obtained on the basis of crystallographic data and a bond-orbital model, which is capable of calculating single bond contributions to the second-order non-linear optical susceptibility. The tensor values thus calculated are in good agreement with experimental data. The influence of energy-band broadening on the non-linear optical susceptibility is not well accounted for in the bond-orbital model.