Electronic structure and total-energy calculations forNiTi2-type structures

The electronic structure and the cohesive properties of the ${\mathrm{NiTi}}_2$-type structure are studied by using first-principles calculations based on the linear-muffin-tin-orbital method. The relative structural stability of the ${\mathrm{NiTi}}_2$ compound among the three different (${\mathrm{MoPt}}_2$-, ${\mathrm{MoSi}}_2$-, and ${\mathrm{NiTi}}_2$-type) structures is studied, bringing to light the effects of the shape approximation to the potential or of the self-consistency. Our calculations are also used to study the stability of the ${\mathrm{NiTi}}_2$-type structure as a function of the number of valence electrons per atom.