On calculation of electronic states in disordered alloys

A new representation of the Green function for a disordered multicomponent substitution alloy is proposed, using which it is easy to separate one-, two-, etc. contributions to this Green function in corresponding equations. Due to this representation we succeed in obtaining common expressions for the configurationally averaged electron Green function with allowance for the electron scattering on clusters formed by an arbitrary number of atoms. The approach used is equally appropriate to described alloys both in the weak binding model, and in the tight binding one.