Semiconductor–metal phase transformation of tetrahedrally coordinated semiconductors

Abstract The standard Drickamer high‐pressure resistance cell has recently been recalibrated. With this recalibration, it is shown that, within experimental uncertainty, the difference in internal energy between the diamond and the β‐tin forms of group IV elements is equal to the difference in energy between the corresponding Penn‐model semiconductor, corrected for d‐core dehybridization for Ge and Sn, and a free electron gas.