Theoretical study on the lattice dynamics and electron phonon interaction of vanadium under high pressures

First-principles calculations are performed for the lattice dynamics and electron–phonon interaction of the body-centred-cubic (bcc) phase of solid vanadium. A remarkable phonon anomaly is found, i.e. frequencies of the transverse mode around a quarter of the Γ–H line show softening with increasing pressure and become imaginary at pressures higher than ∼130 GPa. The superconducting transition temperatures T c of bcc vanadium estimated as a function of pressure increases at first linearly with pressure, and then the rate of increase of T c is abated around 80 GPa. This calculated pressure dependence of T c shows qualitatively the same behaviour as the experimental result.