Equation of state and bulk modulus under pressure of alkali metals

Abstract

Using a local Heine-Abarenkov model potential and perturbational formalism the pressure-volume relation of alkali metals and their bulk modulus under pressure are investigated and compared with the observed data. The agreement for the equation of state between the calculated and experimental data is excellent. For the bulk modulus under pressure, agreement between our obtained results and the few experimental data which used the piston-displacement method is not really satisfactory but the author's calculated data will be useful to describe the typical theoretical bulk modulus. Third-order contributions of the pseudopotential to the pressure and to the bulk modulus are studied, and their effects found not to be essential quantitatively for alkali metals.