BINDING-ENERGY AND COMPRESSIBILITY OF ALKALI-METAL ALLOYS

A general theory for the binding energy and compressibility of binary random alloys is presented, which is applicable to any form of the mod el pseudopotential. The contributions to compressibility from the elec trostatic, kinetic, exchange, correlation, Hartree and overlap energy terms have been explicitly worked out. The contribution from the band structure energy has been bifurcated into two parts, the first due to average lattice and second due to the difference lattice. The theory h as been specialised for the case of linear potential proposed by Sharm a and Kachhava [Solid State Commun 30 (1979) 749]. The RPA form of die lectric screening function is used to account for the behaviour of the electron gas in the alkali metal alloys. The theory has been applied for the calculation of binding energy and compressibility of the seven alkali metal alloys. The results obtained show good agreement with th e experimental data for metallic phases and as well with the other the oretical results.