Unbiasing fermionic auxiliary-field quantum Monte Carlo with matrix product state trial wavefunctions

In this work, we report, for the first time, an implementation of fermionic auxiliary-field quantum Monte Carlo (AFQMC) using matrix product state (MPS) trial wavefunctions, dubbed MPS-AFQMC. Calculating overlaps between an MPS trial and arbitrary Slater determinants up to a multiplicative error, a...

Full description

Saved in:
Bibliographic Details
Main Authors: Tong Jiang, Bryan O'Gorman, Ankit Mahajan, Joonho Lee
Format: Article
Language:English
Published: American Physical Society 2025-01-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/PhysRevResearch.7.013038
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1841546913010155520
author Tong Jiang
Bryan O'Gorman
Ankit Mahajan
Joonho Lee
author_facet Tong Jiang
Bryan O'Gorman
Ankit Mahajan
Joonho Lee
author_sort Tong Jiang
collection DOAJ
description In this work, we report, for the first time, an implementation of fermionic auxiliary-field quantum Monte Carlo (AFQMC) using matrix product state (MPS) trial wavefunctions, dubbed MPS-AFQMC. Calculating overlaps between an MPS trial and arbitrary Slater determinants up to a multiplicative error, a crucial subroutine in MPS-AFQMC, is proven to be #P-hard. Nonetheless, we tested several promising heuristics in successfully improving fermionic phaseless AFQMC energies. We also proposed a way to evaluate local energy and force bias evaluations free of matrix product operators. This allows for larger basis set calculations without significant overhead. We showcase the utility of our approach on one- and two-dimensional hydrogen lattices, even when the MPS trial itself struggles to obtain high accuracy. Our work offers a new set of tools that can solve currently challenging electronic structure problems with future improvements.
format Article
id doaj-art-dff1056e96bc41af9ccde5d925cd8588
institution Kabale University
issn 2643-1564
language English
publishDate 2025-01-01
publisher American Physical Society
record_format Article
series Physical Review Research
spelling doaj-art-dff1056e96bc41af9ccde5d925cd85882025-01-10T15:04:51ZengAmerican Physical SocietyPhysical Review Research2643-15642025-01-017101303810.1103/PhysRevResearch.7.013038Unbiasing fermionic auxiliary-field quantum Monte Carlo with matrix product state trial wavefunctionsTong JiangBryan O'GormanAnkit MahajanJoonho LeeIn this work, we report, for the first time, an implementation of fermionic auxiliary-field quantum Monte Carlo (AFQMC) using matrix product state (MPS) trial wavefunctions, dubbed MPS-AFQMC. Calculating overlaps between an MPS trial and arbitrary Slater determinants up to a multiplicative error, a crucial subroutine in MPS-AFQMC, is proven to be #P-hard. Nonetheless, we tested several promising heuristics in successfully improving fermionic phaseless AFQMC energies. We also proposed a way to evaluate local energy and force bias evaluations free of matrix product operators. This allows for larger basis set calculations without significant overhead. We showcase the utility of our approach on one- and two-dimensional hydrogen lattices, even when the MPS trial itself struggles to obtain high accuracy. Our work offers a new set of tools that can solve currently challenging electronic structure problems with future improvements.http://doi.org/10.1103/PhysRevResearch.7.013038
spellingShingle Tong Jiang
Bryan O'Gorman
Ankit Mahajan
Joonho Lee
Unbiasing fermionic auxiliary-field quantum Monte Carlo with matrix product state trial wavefunctions
Physical Review Research
title Unbiasing fermionic auxiliary-field quantum Monte Carlo with matrix product state trial wavefunctions
title_full Unbiasing fermionic auxiliary-field quantum Monte Carlo with matrix product state trial wavefunctions
title_fullStr Unbiasing fermionic auxiliary-field quantum Monte Carlo with matrix product state trial wavefunctions
title_full_unstemmed Unbiasing fermionic auxiliary-field quantum Monte Carlo with matrix product state trial wavefunctions
title_short Unbiasing fermionic auxiliary-field quantum Monte Carlo with matrix product state trial wavefunctions
title_sort unbiasing fermionic auxiliary field quantum monte carlo with matrix product state trial wavefunctions
url http://doi.org/10.1103/PhysRevResearch.7.013038
work_keys_str_mv AT tongjiang unbiasingfermionicauxiliaryfieldquantummontecarlowithmatrixproductstatetrialwavefunctions
AT bryanogorman unbiasingfermionicauxiliaryfieldquantummontecarlowithmatrixproductstatetrialwavefunctions
AT ankitmahajan unbiasingfermionicauxiliaryfieldquantummontecarlowithmatrixproductstatetrialwavefunctions
AT joonholee unbiasingfermionicauxiliaryfieldquantummontecarlowithmatrixproductstatetrialwavefunctions