Abstract: | An electronic-computer programme has been written by the author for calculations of energy bands in the tight-binding approximation. This programme has been applied to crystals of α zirconium with and without dissolved oxygen. The resulting energy bands and orbital distributions represent an enormous amount of numerical data. Another programme has now also been written by the author for population analysis of the occupied bands. This programme will reduce the resulting output considerably, and only occupied bands are represented in a number of directions in k space. The occupation numbers are summed up for orbitals with equal quantum numbers l and |m|, and are found for each band as a function of k . |