Theory of structural, electronic, vibrational, and superconducting properties of high-pressure phases of sulfur

Abstract

Pseudopotential ab initio calculations are performed for three high-pressure phases of sulfur (bco, β-Po, and bcc). These calculations yield a value of around 550 GPa for the transition pressure of the β-Po to bcc transformation; however, we do not reproduce the reported bco to β-Po phase transition. Ab initio calculations of the phonon spectrum and the electron-phonon interaction for the bcc phase of sulfur are also done using the frozen phonon method. The results predict that the bcc phase of sulfur is a metal with very low resistivity and a superconducting transition temperature of 15 K.