TRANSFERABLE NONORTHOGONAL TIGHT-BINDING SCHEME FOR SILICON

A minimal-parameter tight-binding theory incorporating explicit use of nonorthogonality of the basis, is used to generate a transferable scheme for silicon. Good results are obtained for band structure, phase diagram, and bulk phonons. The diamond structure is found to be the ground state even when compared with the clathrate structure. The results for clusters show good agreement with ab initio predictions. The theory differs from the conventional orthogonal schemes in three main respects: (1) only three adjustable parameters are employed, (2) no artificial cutoff is used for interactions and, (3) the need for a coordination-dependent energy term has been obviated for clusters of any size. © 1994 The American Physical Society.