DIRECT CALCULATIONS OF CHARGE-DENSITIES OF SOLIDS - APPLICATIONS TO THE ALKALI-EARTH SOLIDS

We performed ab initio self-consistent calculations for the five alkali-earth sulfides--BeS, MgS, CaS, SrS, and BaS-by a method which allows the direct calculation of the ground-state electron density without a preliminar determination of the wave functions and of the energy eigenvalues of the system. We report the results for the standard cohesive properties (equilibrium lattice parameters, dissociation energies, bulk moduli), a study of the relative stability of the B1 (NaCl), B2 (CsCl), and B3 (ZnS) phases, and of the behavior under pressure of these compounds (equation of state; pressure and change of volume associated to the structural phase transition B1 --> B2 or B3 --> B1). (C) 1995 John Wiley & Sons, Inc.