^{1} Theoretical Atomic-scale Physics, Department of Physics, Technical University of Denmark^{2} Department of Physics, Technical University of Denmark^{3} Department of Micro- and Nanotechnology, Technical University of Denmark^{4} Brookhaven National Laboratory^{5} Brookhaven National Laboratory

DOI:

10.1103/PhysRevB.50.10727

Abstract:

A method for calculating the total energy of Si systems, which is based on the effective-medium-theory concept of a reference system, is presented. Instead of calculating the energy of an atom in the system of interest, a reference system is introduced where the local surroundings are similar. The energy of the reference system can be calculated self-consistently once and for ah while the energy difference to the reference system can be obtained approximately. We propose to calculate it using the tight-binding linear-muffin-tin-orbital scheme with the atomic-sphere approximation (ASA) for the potential, and by using the ASA with charge-conserving spheres we are able to treat open systems without introducing empty spheres. All steps in the calculational method are ab initio in the sense that all quantities entering are calculated from first principles without any fitting to experiment. A complete and detailed description of the method is given together with test calculations of the energies of phonons, elastic constants, different structures, surfaces, and surface reconstructions. We compare the results to calculations using an empirical tight-binding scheme.

Type:

Journal article

Language:

English

Published in:

Physical Review B Condensed Matter, 1994, Vol 50, Issue 15, p. 10727-10741