First-principles study of the structural properties of alkali metals

Abstract

The structural properties of lithium, sodium, and potassium are studied with use of an ab initio pseudopotential method to calculate the total energies of these systems as a function of volume. The results show very small energy differences between the bcc, fcc, and hcp phases in these materials in good agreement with the measured crystal structures for all three metals. The lattice constants are computed to within 2% of experiment except for sodium where the calculation gives a lattice constant 3% smaller than experiment.