Dispersion relations in some hexagonal metals

Abstract
Dispersion curves of four hexagonal metals Be, Mg, Ho and Tl have been obtained on the basis of a modified Sharma-Joshi model. Agreements with experimental measurements are fairly good in two cases namely Be and Mg but not so good in the other two. However the dispersion curves in the (0001) direction are obtained in almost exact agreement with the experimental ones and the deviations which are largest at the zone boundaries in the (0110) direction are in general not more than 15 per cent.