Semiempirical method for the evaluation of bond covalency in complex crystals

We report a semiempirical method for the evaluation of bond covalency in co mplex crystals. This method is the extension of the dielectric description theory delivered by Phillips, Van Vechten, Levine, and Tanaka (PVLT) which is mainly suitable for binary crystals. Our method offers the advantage of applicability to a broad class of complex materials. The simplicity of the approach allows a broader class of researchers to access the method easily and to calculate not only the bond covalency but also other useful. propert ies such as bulk modulus. For a series study, a useful trend can be illustr ated and often the prediction of the properties of the-missing one(s) among the series can be possible. Finally, examples are given to show how the me thod is applied and the procedure is transferable to other complex crystals .