A Reverse Monte Carlo Study on the Structure of Fluid Hg

The structure of fluid Hg along the liquid-vapour coexistence curve has been modelled by applying the reverse Monte Carlo method to the structural factors recently obtained by x-ray diffraction using synchrotron radiation at SPring-8 J. Non-Cryst. Solids 312-4 (2002) 284. The modelling reveals that the distribution of coordination numbers of the first-neighbour shell, P(N), broadens and shifts to lower values at high temperature and high pressure. The main peak of bond angle distributions function P(cos), located at 60°, is rather sharp at room temperature, but it damps and broadens seriously as temperature increases. When approaching the metal-non-metal transition, P(N) of the atoms with shorter bonds broadens and shifts toward lower values noticeably, but little change occurs for that of longer bonds. The changes of the coordination number and the distribution of the atoms with the shorter bond are closely related to the metal-non-metal transition of fluid Hg.