Coordination and bonding in representatives of the Fe3P-, Ti3P-, α-V3S- and β-V3S-type structures

Abstract A survey of the atomic coordination in the compounds concerned is presented in the form of histograms showing the number and distribution of interatomic distances. This survey reveals certain systematic coordination trends. These are found to correspond to trends in the cohesive strength of the elemental transition metals. On this basis an empirical rule for phosphide representatives can be formulated as follows: the greater the cohesive strength of the parent metal, the smaller is the phosphorus coordination number in the corresponding phosphide. An attempt is made to rationalize this rule in terms of current theories for the chemical bonding in compounds between transition metals and nonmetals with unfilled p levels.