STRUCTURE AND PHASE CHANGES OF GALLIUM

The structure and pressure-induced phase changes of solid Ga are studied in terms of the pseudopotential and second-order perturbation theory. It is shown that the phase changes provide a very sensitive criterion for the pseudopotential form factor, the most important features of which are the position of the first zero and the height and position of the first maximum. The pressure-induced phase changes can be largely understood in these terms, and an explanation is suggested for the formation of a metastable phase when supercooled Ga freezes. The variation of the interionic potential with distance provides a qualitative interpretation of the results.