Partial Structure Factors in Multicomponent Liquid or Amorphous Alloys

The structure of a υ component liquid or amorphous alloy is analyzed in terms of υ(υ+1)/2 independent partial structure factors which are associated to the different correlations between the numbers of particles of all chemical species. This formalism, which is specially adapted to the study of alloys of more than two components, is related to Fournet-Faber-Ziman and extended Bhatia-Thornton theory. Sum rules, inequality relations and limiting values are calculated in the static approximation and Debye pair expressions of the structure factors are derived in the isotropic approximation.