First Principles Theory of short range order and electronic excitations in Ni-Vand Pd-V alloys

(iv) We provide predictions of the SRO patterns where there is currently no experimental evidence for Pd{sub 0.67}V{sub 0.33}, Ni{sub 0.6}V{sub 0.4}, Pd{sub 0.6}V{sub 0.4}, and Pd{sub 0.5}V{sub 0.5}. (v) For Ni{sub 3}V and Pd{sub 3}V, discrepancies are found between the total-energy differences of the {ital L}1{sub 2} and {ital D}0{sub 22} structures as determined by {ital T}=0 first-principles calculations and those inferred from diffuse neutron scattering measurements at high {ital T}. By performing temperature-dependent self-consistent local-density-approximation calculations, we find that electronic excitations are responsible for reducing the discrepancy by {similar_to}25% and the combination of spin polarization and electronic excitations reduce the discrepancy by {similar_to}30--50 %. Thus, electronic excitations and spin polarization are not fully responsible for the {ital T} dependence of {ital J}{sub {ital f}} used in the SRO calculations.