A Pseudopotential Approach to the Crystal Energy of Si

The pseudopotential of Si crystal is determined self-consistently from the Topp-Hopfield type model potential of Si atom by using the Slater approximation. The crystal energy and compressibility are calculated on the basis of the resultant band structure and the charge density. A good agreement between the calculated values and the experimental ones is obtained with no adjustment such as the zero pressure condition nor fitting to the band structure near the fundamental band gap as done in the usual empirical pseudopotential methods.