Pressure-induced distortion of the β-Sn phase in silicon: Effects of nonhydrostaticity

Studies of phase transitions under pressure usually assume perfect hydrostatic conditions but it is far from being true in practice. Theoretical calculations based on a tight-binding model prove that nonhydrostatic conditions can significantly reduce the Si II to Si XI transition pressure. This distortion induced by nonhydrostaticity was already observed in high-pressure experiments (in the case of GaSb and InSb), and so this work is the theoretical confirmation of the possibility of such a phenomenon.