Coordination and volume changes accompanying high-pressure phase transformations of oxides

Abstract

Although attention has always been given to changes of cation coordination in high-pressure phase transformations, changes of anion coordination have generally been ignored even though they are as characteristic and probably as important as those of the cations. The importance of the anion coordination change is illustrated for transformations of In203 and the transition metal molybdates. The relative change of molar volume or density can frequently be used to distinguish high-pressure phase transformations involving a coordination change from those not involving a coordination change.