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%.