d-Electron Effects on Bond Susceptibilities and Ionicities

Abstract

We have been able to extend the dielectric theory of ionicity to include such $d$-electron systems as the noble-metal halides (e.g., CuCl, AgBr, etc.), $AB$ transition-metal compounds (e.g., ScN, MnS, FeO, NiO, etc.), $A_m{B}_n$ crystals (e.g., Zr${\mathrm{F}}_4$, Ti${\mathrm{O}}_2$, ${\mathrm{Cr}}_2$ ${\mathrm{O}}_3$, ${\mathrm{Fe}}_2$ ${\mathrm{O}}_3$), and multibond compounds (e.g., LiNb${\mathrm{O}}_3$, LiTa${\mathrm{O}}_3$, CuGa${\mathrm{S}}_2$, CuIn${\mathrm{S}}_2$, AgGa${\mathrm{Se}}_2$, AgIn${\mathrm{Se}}_2$). This characterization of the ionicity and other bond parameters should be useful in some of the wide variety of problems to which the non-$d$-electron theory has already been successfully applied, e.g., the calculation of nonlinear optical susceptibilities.