Total energies and magnetic moments in Fe, V, and ordered FeV

First-principles band calculations based on the augmented-spherical-wave method and the fixed-spin-moment procedure are used to determine the volume dependence of the total energy, the spin-polarization energy, and the local magnetic moments of bcc iron and vanadium and ordered FeV in the CsCl structure. At compressed volumes, FeV shows a second-order transition from nonmagnetic to magnetic behavior similar to bcc iron. For FeV, the calculations yield a theoretical lattice constant that is 1.4% below the experimental value, and iron and vanadium local moments of 0.66${\mathrm{\mu }}_{\mathit{B}}$ and zero, respectively, in agreement with neutron-diffraction measurements. The local moments are antiparallel at large volumes and parallel at small volumes, and the vanadium local moment vanishes at or near the theoretical equilibrium volume. The bulk modulus of FeV is found to be larger than that of both bcc vanadium and spin-polarized iron and is close to the average of vanadium and non-spin-polarized iron.