Application of the Z method to transition metals

The calculation of transition metal melt curves to high pressure is a computationally demanding task. In this work, the ab initio Z method has been employed to calculate the melt curves of Ti and V to 100 GPa. These calculations show some support for the measurements of Errandonea et al. [PRB 63, 132104 (2001)]. The melt curve of Ta has has been calculated to 250 GPa. In this case, good agreement is found with the measurements of Dewaele et al. [PRL, 104, 25570 (2010)], which extend to 135 GPa and show a more rapid rise of the melting temperature with increasing pressure than the measurements of Errandonea et al. However, above 150 GPa the calculated melt curve flattens considerably with the melt temperature showing a relatively small rise to 250 GPa.