HIGH PRESSURE BEHAVIOR OF KCl: STRUCTURAL AND ELECTRONIC PROPERTIES

The high pressure behavior of the structural and electronic properties of KC1 is studied with use of the density functional pseudopotential method within local-density approximation. Atzero pressure, the rocksalt phase is found to be lower in energy than CsCl structure. However, we predict a phase transition into CsCI structure at a pressure of about 1.5 GPa. The calculated ground state properties such as lattice constant, bulk modulus, and its pressure derivative are in reasonable agreement with experiment. The electronic band structure at normal and high pressures is also calculated. It is found that metallization occurs for rocksalt and CsCI structures at ultrahigh pressures