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Title: Interaction picture density matrix quantum Monte Carlo

Journal Article · · Journal of Chemical Physics
DOI:https://doi.org/10.1063/1.4927434· OSTI ID:22493901
;  [1];  [2];  [1];  [1]
  1. Department of Physics, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom)
  2. University Chemical Laboratory, Cambridge University, Lensfield Road, Cambridge CB2 1EW (United Kingdom)

The recently developed density matrix quantum Monte Carlo (DMQMC) algorithm stochastically samples the N-body thermal density matrix and hence provides access to exact properties of many-particle quantum systems at arbitrary temperatures. We demonstrate that moving to the interaction picture provides substantial benefits when applying DMQMC to interacting fermions. In this first study, we focus on a system of much recent interest: the uniform electron gas in the warm dense regime. The basis set incompleteness error at finite temperature is investigated and extrapolated via a simple Monte Carlo sampling procedure. Finally, we provide benchmark calculations for a four-electron system, comparing our results to previous work where possible.

OSTI ID:
22493901
Journal Information:
Journal of Chemical Physics, Vol. 143, Issue 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
Country of Publication:
United States
Language:
English