AB-INITIO ANALYSIS OF STRUCTURAL STABILITY IN THE COMPOUND NI3V

Ab initio total energies and electronic band-structure calculations ha ve been performed for the compound Ni3V with the L1(2) and D0(22) stru cture type. Using a ''frozen potential'' method, we show that the rela tive structural stability can be analyzed in terms of the density of s tates which indicates that the D0(22) structure tends to exist when th e concentration of valence electrons per atom exceeds 8.65. We find an important discrepancy between the total energy differences of the L1( 2) and D0(22) structures as determined by T=0 first-principles calcula tions and those deduced from diffuse neutron-scattering measurements a t T=1374 K. Including thermal excitations and spin-polarization effect s reduce the discrepancy by only 20%.