| With today's powerful computers, simulations have become an extremely useful means for studying complex solid systems. This work covers three aspects of computer simulation of semiconductor alloys: (1) molecular dynamics simulations of structural properties. (2) Monte Carlo simulations of alloy phase diagrams and, (3) development of an efficient and accurate ab-initio total energy method. Detailed bond lengths, bond angles, and excess energies of pseudobinary semiconductor alloys along with a direct visualization of the atomic positions have been obtained from the molecular dynamics simulations. A general procedure has been developed to obtain the temperature and concentration dependant free energy of bulk alloys from finite size Monte Carlo simulations. In order to perform first principle simulations, an efficient and accurate total energy code based on local density approximation and compact orbitals has been developed. These developments, when coupled with a newly developed linear-scale algorithm, may be capable of performing large-scale atomistic simulations to predict properties and new structures of complex materials for which no experimental information is available. |
