Band structure calculations in isoelectronic B compounds: BNi, Pd and Pt

In the isoelectronic compounds V 3 Ni, V 3 Pd and V 3 Pt the chemical bonding is ruled by the σ -type interactions of the V d-orbitals. It is observed that there is a tendency to form degenerate bands at the X and M points in the irreducible part of the Brillouin zone. An estimation of the electron–phonon coupling constant λ  yields 0.48 for V 3 Ni, 0.42 for V 3 Pd and 0.76 for V 3 Pt. From Ni to Pt the unsystematic behavior experimentally observed for the unit cell volume arises from a competition mechanism between strengthening of interactions of bonding states and increasing atomic volumes.