Simple semi-empirical method for evaluating bond polarity in molecular and crystalline halides

It is suggested to determine the degree of electron transfer between metal M and nonmetal X in MXn halides from equalization of the M ionization potential and the X electron affinity, i.e. from the point of intersection between the curves describing the ionization potential (for metals) and electron affinity (for nonmetals) as a function of ionization degree (bond ionicity).