Empirical Third Neighbour LCAO Energy Bands of Silicon

A third nearest neighbour LCAO description, including overlap integrals, is constructed for the energy bands of silicon. The overlap integrals are calculated from Slater‐type atomic orbitals, the interaction integrals and the screening parameter are determined empirically by fitting the bands to recent adjusted OPW calculations. Good overall agreement is obtained. The second nearest neighbour interaction integrals obtained cannot be derived from two‐center integrals only. Previous failures to obtain reasonable bands for diamond and silicon by the empirical LCAO scheme are briefly discussed.