physics pp. 153{158 Total energy, equation of state and bulk modulus

Abstract. Recently proposed model potential which combines both linear and quadratic types of interactions is employed for the investigation of some properties like the total en-ergy, equation of state and bulk modulus of AlP, AlAs and AlSb semiconductor compounds using higher-order perturbation theory. The model potential parameter is determined us-ing zero pressure condition. The ratio of the covalent bonding term Ecov to the second-order term E2 is 6.77 % to 11.85 % which shows that contribution from higher order terms are important for zinc-blende-type crystals. The calculated numerical results of the total energy, energy band gap at Jones-zone face and bulk modulus of these compounds are in good agreement with the experimental data and found much better than other such theoretical ¯ndings. We have also studied pressure{volume relations of these compounds. The present study is carried out using six di®erent screening functions along with latest screening function proposed by Sarkar et al. It is found from the present study that e®ect of exchange and correlation is clearly distinguishable