A large unit cell semiempirical molecular orbital approach to the properties of solids. II. Covalent materials: diamond and silicon

For pt.I see ibid., vol.12, p.2487 (1979). Some properties of diamond and silicon crystals have been calculated using a large unit cell-complete neglect of differential overlap (LUC-CNDO) crystal orbital approach. The dependence of the predictions on the parameter set chosen, on the size and shape of the large unit cell and on the cut-off distance for atomic interactions has been investigated. The results obtained for the perfect solid with a near-optimum parameter set are, in general, in good agreement with experimental values.