The high pressure phase transition of silicon

Full text: At a pressure of 10 GPa silicon undergoes a phase transition from the four-fold coordinated diamond structure to a six-fold coordinated β-Sn structure. This phase transition is first order and corresponds to a 25% volume reduction. Several atomic mechanisms have been suggested for this transition but none have explicitly included the effects of macroscopic strain induced in the crystal by such as dramatic volume collapse. I will present results of a computational study to determine the energy barrier for an atomic mechanism which preserves the strain of the (111) plane of the diamond structure