Self-consistently determined properties of solids without band-structure calculations

We propose an approach to the calculation of the cohesive and the structural properties of solids. This approach is based on the second theorem of Hohenberg and Kohn and allows one to obtain directly the charge density and the total energy without determining, at the same time, the band structure of the system. The method is easy to implement, is self-consistent, and suggests a meaning for concepts such as ‘‘atoms in solids,’’ ‘‘crystalline field,’’ and ‘‘charge transfer,’’ which are not, in general, well defined in the context of ab initio calculations. The results of applications to some alkali halide crystals are compared with the corresponding results obtained by several authors using traditional techniques for band-structure calculations.