English

An efficient method for grand-canonical twist averaging in quantum Monte Carlo calculations

Materials Science 2020-01-01 v1 Statistical Mechanics Chemical Physics

Abstract

We introduce a simple but efficient method for grand-canonical twist averaging in quantum Monte Carlo calculations. By evaluating the thermodynamic grand potential instead of the ground state total energy, we greatly reduce the sampling errors caused by twist-dependent fluctuations in the particle number. We apply this method to the electron gas and to metallic lithium, aluminum, and solid atomic hydrogen. We show that, even when using a small number of twists, grand-canonical twist averaging of the grand potential produces better estimates of ground state energies than the widely used canonical twist-averaging approach.

Keywords

Cite

@article{arxiv.1910.06814,
  title  = {An efficient method for grand-canonical twist averaging in quantum Monte Carlo calculations},
  author = {Sam Azadi and W. M. C. Foulkes},
  journal= {arXiv preprint arXiv:1910.06814},
  year   = {2020}
}