Reproducibility of fixed-node diffusion Monte Carlo across diverse community codes: The case of water–methane dimer

F Flaviano Della Pia (Yusuf Hamied Department of Chemistry, University of Cambridge 7 , Lensfield Road, Cambridge,) B Benjamin X. Shi (Yusuf Hamied Department of Chemistry, University of Cambridge 7 , Lensfield Road, Cambridge,) Y Yasmine S. Al-Hamdani (Department of Earth Sciences, University College London , London WC1E 6BT, and , Monte S. Angelo, I-80126 Napoli,) D Dario Alfè (Department of Earth Sciences and London Centre for Nanotechnology, University College London, Gower Street, London WC1E 6BT, U.K.) T Tyler A. Anderson (Laboratory of Atomic and Solid State Physics, Cornell University 4 , Ithaca, New York 14853,) M Matteo Barborini (HPC Platform, University of Luxembourg 1 , L-4364 Esch-sur-Alzette,) A Anouar Benali M Michele Casula (Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie) N Neil D. Drummond (Department of Physics, Lancaster University 8 , Lancaster LA1 4YB,) M Matúš Dubecký (Department of Physics, Faculty of Science, University of Ostrava 9 , 30. Dubna 22, 701 03 Ostrava,) C Claudia Filippi (MESA+ Institute for Nanotechnology, University of Twente 1 , P.O. Box 217, 7500 AE Enschede,) P Paul R. C. Kent (Computational Sciences and Engineering Division, Oak Ridge National Laboratory 11 , Oak Ridge, Tennessee 37831,) J Jaron T. Krogel (Materials Science and Technology Division) P Pablo López Ríos (Max-Planck Institute for Solid State Research 1 , Heisenbergstr. 1, 70569 Stuttgart,) A Arne Lüchow (Institute of Physical Chemistry, RWTH Aachen University 14 , Landoltweg 2, 52074 Aachen,) Y Ye Luo A Angelos Michaelides L Lubos Mitas (Department of Physics, North Carolina State University , Raleigh, North Carolina 27695-8202,) K Kousuke Nakano (Center for Basic Research on Materials (CBRM), National Institute for Materials Science (NIMS) 1 , 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047,) R Richard J. Needs (Theory of Condensed Matter Group, Cavendish Laboratory 17 , J. J. Thomson Avenue, Cambridge CB3 0HE,) M Manolo C. Per (CSIRO Data61, Clayton 18 , VIC 3168,) A Anthony Scemama (Laboratoire de Chimie et Physique Quantiques - UMR5626, CNRS/Université Paul Sabatier, Bat. 3R1b4 2 , 118 route de Narbonne, 31062 Toulouse Cedex 09,) J Jil Schultze (Institute of Physical Chemistry, RWTH Aachen University 14 , Landoltweg 2, 52074 Aachen,) R Ravindra Shinde (MESA+ Institute for Nanotechnology, University of Twente 10 , Enschede 7500 AE,) E Emiel Slootman (MESA+ Institute for Nanotechnology, University of Twente 1 , P.O. Box 217, 7500 AE Enschede,) S Sandro Sorella (International School for Advanced Studies (SISSA) 2 , Via Bonomea 265, 34136 Trieste,) A Alexandre Tkatchenko M Mike Towler (The Apuan Alps Centre for Physics 22 , Vallico Sotto,) C C. J. Umrigar (Laboratory of Atomic and Solid State Physics, Cornell University 4 , Ithaca, New York 14853,) L Lucas K. Wagner (Department of Physics, University of Illinois at Urbana-Champaign 23 , Urbana, Illinois 61801,) W William A. Wheeler (Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign 24 , Urbana, Illinois 61801,) H Haihan Zhou (Department of Physics, NC State University 25 , Raleigh, North Carolina 27606,) A Andrea Zen

Abstract

Fixed-node diffusion quantum Monte Carlo (FN-DMC) is a widely trusted many-body method for solving the Schrödinger equation, known for its reliable predictions of material and molecular properties. Furthermore, its excellent scalability with system complexity and near-perfect utilization of computational power make FN-DMC ideally positioned to leverage new advances in computing to address increasingly complex scientific problems. Even though the method is widely used as a computational gold standard, reproducibility across the numerous FN-DMC code implementations has yet to be demonstrated. This difficulty stems from the diverse array of DMC algorithms and trial wave functions, compounded by the method’s inherent stochastic nature. This study represents a community-wide effort to assess the reproducibility of the method, affirming that yes, FN-DMC is reproducible (when handled with care). Using the water–methane dimer as the canonical test case, we compare results from eleven different FN-DMC codes and show that the approximations to treat the non-locality of pseudopotentials are the primary source of the discrepancies between them. In particular, we demonstrate that, for the same choice of determinantal component in the trial wave function, reliable and reproducible predictions can be achieved by employing the T-move, the determinant locality approximation, or the determinant T-move schemes, while the older locality approximation leads to considerable variability in results. These findings demonstrate that, with appropriate choices of algorithmic details, fixed-node DMC is reproducible across diverse community codes—highlighting the maturity and robustness of the method as a tool for open and reliable computational science.

Article Details

Volume / Issue Vol. 163, Issue 10
Published September 14, 2025
ISSN 0021-9606
Publisher American Institute of Physics

Journal Info

The Journal of Chemical Physics

American Institute of Physics

ISSN: 0021-9606 Physical Sciences

Authors (33)

F

Flaviano Della Pia

Yusuf Hamied Department of Chemistry, University of Cambridge 7 , Lensfield Road, Cambridge,

B

Benjamin X. Shi

Yusuf Hamied Department of Chemistry, University of Cambridge 7 , Lensfield Road, Cambridge,

Y

Yasmine S. Al-Hamdani

Department of Earth Sciences, University College London , London WC1E 6BT, and , Monte S. Angelo, I-80126 Napoli,

D

Dario Alfè

Department of Earth Sciences and London Centre for Nanotechnology, University College London, Gower Street, London WC1E 6BT, U.K.

T

Tyler A. Anderson

Laboratory of Atomic and Solid State Physics, Cornell University 4 , Ithaca, New York 14853,

M

Matteo Barborini

HPC Platform, University of Luxembourg 1 , L-4364 Esch-sur-Alzette,

A

Anouar Benali

M

Michele Casula

Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie

N

Neil D. Drummond

Department of Physics, Lancaster University 8 , Lancaster LA1 4YB,

M

Matúš Dubecký

Department of Physics, Faculty of Science, University of Ostrava 9 , 30. Dubna 22, 701 03 Ostrava,

C

Claudia Filippi

MESA+ Institute for Nanotechnology, University of Twente 1 , P.O. Box 217, 7500 AE Enschede,

P

Paul R. C. Kent

Computational Sciences and Engineering Division, Oak Ridge National Laboratory 11 , Oak Ridge, Tennessee 37831,

J

Jaron T. Krogel

Materials Science and Technology Division

P

Pablo López Ríos

Max-Planck Institute for Solid State Research 1 , Heisenbergstr. 1, 70569 Stuttgart,

A

Arne Lüchow

Institute of Physical Chemistry, RWTH Aachen University 14 , Landoltweg 2, 52074 Aachen,

Y

Ye Luo

A

Angelos Michaelides

L

Lubos Mitas

Department of Physics, North Carolina State University , Raleigh, North Carolina 27695-8202,

K

Kousuke Nakano

Center for Basic Research on Materials (CBRM), National Institute for Materials Science (NIMS) 1 , 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047,

R

Richard J. Needs

Theory of Condensed Matter Group, Cavendish Laboratory 17 , J. J. Thomson Avenue, Cambridge CB3 0HE,

M

Manolo C. Per

CSIRO Data61, Clayton 18 , VIC 3168,

A

Anthony Scemama

Laboratoire de Chimie et Physique Quantiques - UMR5626, CNRS/Université Paul Sabatier, Bat. 3R1b4 2 , 118 route de Narbonne, 31062 Toulouse Cedex 09,

J

Jil Schultze

Institute of Physical Chemistry, RWTH Aachen University 14 , Landoltweg 2, 52074 Aachen,

R

Ravindra Shinde

MESA+ Institute for Nanotechnology, University of Twente 10 , Enschede 7500 AE,

E

Emiel Slootman

MESA+ Institute for Nanotechnology, University of Twente 1 , P.O. Box 217, 7500 AE Enschede,

S

Sandro Sorella

International School for Advanced Studies (SISSA) 2 , Via Bonomea 265, 34136 Trieste,

A

Alexandre Tkatchenko

M

Mike Towler

The Apuan Alps Centre for Physics 22 , Vallico Sotto,

C

C. J. Umrigar

Laboratory of Atomic and Solid State Physics, Cornell University 4 , Ithaca, New York 14853,

L

Lucas K. Wagner

Department of Physics, University of Illinois at Urbana-Champaign 23 , Urbana, Illinois 61801,

W

William A. Wheeler

Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign 24 , Urbana, Illinois 61801,

H

Haihan Zhou

Department of Physics, NC State University 25 , Raleigh, North Carolina 27606,

A

Andrea Zen