Calculations showing a correlation between electronic density and bulk modulus in fcc and bcc metals

The linearized augmented-plane-wave method is used to study the electronic density nWS at the boundary of the Wigner-Seitz cell for bcc and fcc elemental metals. The calculated nWS is generally in good agreement with the results derived from an empirical formula that was introduced by Miedema and co-workers. A formula is introduced to calculate the bulk modulus of materials using nWS, and from it another formula for calculating the relationship between the external pressure and the volume of materials is derived. As an example, the pressure-volume compression curve for Cu is calculated. The limitations and features of the conventional method and our method for calculating the bulk modulus of materials are discussed.