Journal article
Piecewise interaction picture density matrix quantum Monte Carlo
The Journal of chemical physics, Vol.156(18), 184107
05/14/2022
DOI: 10.1063/5.0094290
Abstract
The density matrix quantum Monte Carlo (DMQMC) set of methods stochastically samples the exact N-body density matrix for interacting electrons at finite temperature. We introduce a simple modification to the interaction picture DMQMC (IP-DMQMC) method that overcomes the limitation of only sampling one inverse temperature point at a time, instead allowing for the sampling of a temperature range within a single calculation, thereby reducing the computational cost. At the target inverse temperature, instead of ending the simulation, we incorporate a change of picture away from the interaction picture. The resulting equations of motion have piecewise functions and use the interaction picture in the first phase of a simulation, followed by the application of the Bloch equation once the target inverse temperature is reached. We find that the performance of this method is similar to or better than the DMQMC and IP-DMQMC algorithms in a variety of molecular test systems.
Details
- Title: Subtitle
- Piecewise interaction picture density matrix quantum Monte Carlo
- Creators
- William Z. Van Benschoten - University of IowaJames J. Shepherd - University of Iowa
- Resource Type
- Journal article
- Publication Details
- The Journal of chemical physics, Vol.156(18), 184107
- DOI
- 10.1063/5.0094290
- ISSN
- 0021-9606
- eISSN
- 1089-7690
- Number of pages
- 9
- Grant note
- DE-SC0021317; DE-AC02-05CH11231 / U.S. Department of Energy (https://doi.org/10.13039/100000015)
- Date published
- 05/14/2022
- Academic Unit
- Chemistry
- Record Identifier
- 9984257635702771
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