ELECTRONIC AND STRUCTURAL-PROPERTIES OF MGS AND MGSE

A detailed description of the electronic band structures of MgS and Mg Se were investigated using the tight binding linear muffintin orbital method. The calculations were done in the zinc blende (B3) and the NaC l-type (B1) structures. The calculated ground-state properties were fo und to be in agreement with the experimental values. Under compression both MgS and MgSe are found to undergo a structural phase transition from the B3 to the B1 structure at pressures of 377 and 317 kbar, resp ectively. At ambient conditions both MgS and MgSe are found to be indi rect band gap semiconductors and exhibit the phenomenon of metallizati on at about 50% volume compression.