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 n_WS at the boundary of the Wigner-Seitz cell for bcc and fcc elemental metals. The calculated n_WS 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 n_WS, 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.