A PARALLEL CRN MODELING SYSTEM

An extension to the bond rearrangement method introduced by Wooten, Winer and Weaire (the www algorithm), which uses a simple algorithm to create structural models of tetrahedrally bonded amorphous materials such as amorphous silicon or germanium, has been developed using a parallel architecture. A continuous random network (CRN) model is produced by first introducing randomized arrangements in a systematic way in a crystal lattice, restricting the creation of ring structures within the lattice to five-, six- and seven-membered rings. A systematic, optimum simulated annealing process is then applied to relax the structure to a low energy. A model created using the process is compared with experiment, and with a model created using the original algorithm. The improvements allow the WWW algorithm to be run on more modest computer technology. The system has been implemented in FORTRAN, on a MEIKO computing surface multi-transputer system using CSTools for the extension to a parallel architecture.