An efficient and accurate perturbative correction to initiator full configuration interaction quantum Monte Carlo
Chemical Physics
2018-06-13 v3 Strongly Correlated Electrons
Computational Physics
Abstract
We present a perturbative correction within initiator full configuration interaction quantum Monte Carlo (i-FCIQMC). In the existing i-FCIQMC algorithm, a significant number of spawned walkers are discarded due to the initiator criteria. Here we show that these discarded walkers have a form that allows calculation of a second-order Epstein-Nesbet correction, that may be accumulated in a trivial and inexpensive manner, yet substantially improves i-FCIQMC results. The correction is applied to the Hubbard model, the uniform electron gas and molecular systems.
Keywords
Cite
@article{arxiv.1804.09528,
title = {An efficient and accurate perturbative correction to initiator full configuration interaction quantum Monte Carlo},
author = {Nick S. Blunt},
journal= {arXiv preprint arXiv:1804.09528},
year = {2018}
}
Comments
5 pages, 1 figure, with Supplementary material also included