Abstract
The empirical database of Villars and Calvert on the structures of pseudobinary and ternary phases is ordered within a limited number of two dimensional plots by using the recently proposed Mendeleev number M, which takes a unique value for each element in the periodic table. The pseudobinaries are characterised by average Mendeleev numbers MA and MB. The structure maps (MA, MB) for the AB and AB3 stoichiometries respectively are found to display similar domains of structural stability as those of the pure binaries. Most of the non H, C, N, or O containing phases of ternary structure type having more than one representative compound each can be displayed and separated within only seven two dimensional plots. Two each are required for the boride and chalcogenide structure types and a further three for the remaining ternary phases. The importance of these plots for the design of new alloys is stressed. MST/814