An optimized initialization algorithm to ensure accuracy in quantum Monte Carlo calculations

: Quantum Monte Carlo (QMC) calculations require the generation of random electronic configurations with respect to a desired probability density, usually the square of the magnitude of the wavefunction. In most cases, the Metropolis algorithm is used to generate a sequence of configurations in a Markov chain. This method has an inherent equilibration phase, during which the configurations are not representative of the desired density and must be discarded. If statistics are gathered before the walkers have equilibrated, contamination by nonequilibrated configurations can greatly reduce the accuracy of the results. Because separate Markov chains must be equilibrated for the walkers on each processor, the use of a long equilibration phase has a profoundly detrimental effect on the efficiency of large parallel calculations. The stratified atomic walker initialization (STRAW) shortens the equilibration phase of QMC calculations by generating statistically independent electronic configurat...

• Type: Journal
• Year: 2008
• Where: JCC
• Authors: Daniel R. Fisher, David R. Kent IV, Michael T. Feldmann, William A. Goddard III
• Keywords: Calculations, Configurations, Equilibration Phase, JCC 2008