Theoretical studies of the first-row transition metal phosphides

The electronic structures and spectroscopic parameters of the ground and some low-lying excited states of the first-row transition metal phosphides have been calculated with the density functional theory using the Becke three-parameter hybrid exchange functional with the Lee–Yang–Parr correlation functional (B3LYP). The ground states of the transition metal phosphides are found to be Σ+1 (ScP), Δ2 (TiP), Δ3 (VP), Σ−4 (CrP), Π2 (MnP), Σ+6 (FeP), Δ5 (CoP), Δ4 (NiP), and Σ−3 (CuP). The B3LYP functional predicts an increase in covalent character in the bonds between the metal and the phosphorus across the transition metal series. The energies of the low-lying excited states relative to the ground state for TiP, FeP, and CoP have been found to be so small that many low-lying states are possible candidates to be the ground state.