E sub cov - a new tool for the analysis of electronic structure data in a chemical language

It is shown that a generalization of the covalent bond energy of the tight-binding bond model to the case of a non-orthogonal basis set is an appropriate tool to describe the bonding properties of solids in a chemical language. It does not suffer from problems related to the ill-defined average electrostatic potential in periodic systems, in contrast to the formerly proposed crystal orbital Hamilton population (COHP). The new tool is applied to discuss the stability of the bcc, fcc and hcp structures of Nb, Mo, Ru and Rh.