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 F-H line show softening with increasing pressure and become imaginary at pressures higher than similar to 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.