The role of the electrons-per-atom ratio in the structural stability of certain binary alloys

Reports on the structural phase stability of certain binary alloys of less simple metals. The results show that the one-electron contribution arising from the virtual crystal approximation dominates the structural prediction for some of the phases observed in these systems. The neutral object contribution describing the residual interaction of the pseudo-atoms simply reflects the concentration behaviour of the one-electron contribution. The calculations re-emphasise that the first non-vanishing reciprocal lattice vectors g and the diameter of the free electron Fermi sphere 2k_F play a crucially important role in the structural energetics of the systems they consider.