Charge density topology and its relationship to properties in intermetallic alloys

The existence of relationships between structure and properties provides one avenue permitting the design of materials with chosen properties. Unfortunately, rules relating the properties of intermetallic alloys to their crystal structure have not been forthcoming. We believe that this is because the structure of intermetallic alloys is interpreted too narrowly. By extending the definition of structure to include elements of the electronic charge distribution we show, through examples, that there may in fact be relationships between intrinsic mechanical properties and this extended structure. A description of this extended structure requires only a knowledge of the critical points of the total charge density. This knowledge can be obtained through any method of electronic structure or, in principle, through experimental techniques.