Ab initio path integral Monte Carlo approach to the momentum distribution of the uniform electron gas at finite temperature without fixed nodes
Ab initio path integral Monte Carlo approach to the momentum distribution of the uniform electron gas at finite temperature without fixed nodes
Dornheim, T.; Böhme, M.; Militzer, B.; Vorberger, J.
Abstract
We present extensive new ab initio path integral Monte Carlo results for the momentum distribution function n(k) of the uniform electron gas in the warm dense matter regime over a broad range of densities and temperatures. This allows us to study the nontrivial exchange-correlation-induced increase of low-momentum states around the Fermi temperature, and to investigate its connection to the related lowering of the kinetic energy compared to the ideal Fermi gas. In addition, we investigate the impact of quantum statistics on both n(k) and the off-diagonal density matrix in coordinate space, and find that it cannot be neglected even in the strongly coupled electron liquid regime. Our results were derived without any nodal constraints, and thus constitute a benchmark for other methods and approximations.
Keywords: path integral Monte Carlo; uniform electron gas; momentum distribution; warm dense matter
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Physical Review B 103(2021), 205142
DOI: 10.1103/PhysRevB.103.205142
Cited 23 times in Scopus
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Permalink: https://www.hzdr.de/publications/Publ-33430