TOTAL ENERGY, LATTICE-DYNAMICS, AND STRUCTURAL PHASE-TRANSITIONS IN SILICON BY THE ORTHOGONALIZED LINEAR COMBINATION OF ATOMIC ORBITALS METHOD

We demonstrate the accuracy of the self-consistent orthogonalized linear combination of atomic orbitals method within the local-density approximation by applying it to ten different phases of Si. The electronic properties, total energies, and possible structural phase transitions are studied. Also calculated are the static properties of the diamond-structure Si including the equilibrium lattice constant, bulk modulus, and the pressure derivative of the bulk modulus along with the lattice dynamical properties of a few selective phonons at the zone-center and the edge X points of the Brillouin zone. Furthermore, we have evaluated the internal strain parameter of the diamond-structure Si along the [111] direction. The results of our calculations are in very good agreement with the measured values and the results of the pseudopotential calculations. © 1990 The American Physical Society.