First-Principles Study For High-Pressure Tellurium Near A Transition From Bcc To Fcc

We investigated the structural phase transition of Tellurium under high-pressure from the body-centered cubic (bcc) to the face-centered cubic (fcc) structure. Experimentally, it has been reported that the bcc structure is transformed to the fcc structure and coexist with the double hexagonal closed packed (dhcp) structure in the range from 100 to 255 GPa. We performed first-principles structure searching, and found that the bcc, fcc, dhcp, and hcp structures are the four lowest enthalpy structures from 50 to 500 GPa. We confirmed that the bcc structure transforms to the fcc structure and the dhcp structure is the second lowest enthalpy structure. The transition pathway from the bcc to fcc structure has been confirmed to be a tetragonal pathway, which is caused by a uniaxial distortion from total energy calculations.