High-pressure behavior of phosphorus from first principles calculations

High-pressure structural behavior, electronic structure, and vibrational properties of P have been investigated by means of first principles calculations. We perform an ab initio search for the P-IV phase by analyzing the phonon dispersions of the simple cubic (sc) structure as a function of pressure. In particular, we use the dynamical instability of the sc structure above the transition into the simple hexagonal structure to extract a possible candidate structure for P-IV. Additionally, in contrast to general expectations, we show that the body-centered cubic (bcc) P-V phase cannot be the end member of the high-pressure structural sequence of P because it becomes dynamically unstable at high compression. We propose that at ultrahigh pressure above 2800.3em0exGPa, the bcc structure transforms first to the $IM7$ structure and then to the hexagonal close-packed structure.