High-pressure phases of Sn are investigated with use of the first-principles pseudopotential total-energy method. The T=0 calculations accurately reproduce the structural parameters of the low-pressure modifications α-Sn and β-Sn and predict a transition to either bcc or bct at high pressure. The calculated compression ratio of the body-centered phase at high pressure also agrees well with experiment.

• Received 21 November 1990

DOI:https://doi.org/10.1103/PhysRevB.43.9251