Atomic and electronic structure of the stable Ge2Sb2Te5 compound

Ab initio calculations, based on pseudopotentials and density functional theory, have been performed to investigate the atomic and electronic structure of the Ge2Sb2Te5 compound. Two different possible models have been considered. From total energy calculations, it has been found that one of this models is energetically favorable than the other model. The electronic band structure calculations for the second model showed that the system exhibits a semiconductor character. The bonding character of the system is also been examined. All results are seen to be in agreement with the other theoretical and experimental datas