Space warp coordinate transformation for efficient ionic force calculations in quantum Monte Carlo

ORAL

Abstract

Although ab-initio quantum Monte Carlo (QMC) ground-state energy calculation is standard and widely used in physics and chemistry, calculation of atomic forces is still under technical/algorithmic development. We have benchmarked the accuracy of all-electron variational Monte Carlo (VMC) and lattice regularized diffusion Monte Carlo (LRDMC) forces for various mono- and hetero-nuclear dimers. The VMC and LRDMC forces were calculated with the so-called space warp coordinate transformation (SWCT) and appropriate regularization techniques to remove the infinite variance problem. We have found that the appropriate use of the SWCT transformation makes the calculation of forces very efficient and feasible also for large atomic number. This is a quite promising conclusion from the viewpoint of the application of QMC forces, opening the door for future important applications of QMC in electronic structure calculations.

*The computations in this work have been mainly performed using the supercomputer Fugaku provided by RIKEN through the HPCI System Research Project (Project ID: hp210038). This work is also supported by the European Centre of Excellence in Exascale Computing TREX - Targeting Real Chemical Accuracy at the Exascale. This project has received funding from the European Union's Horizon 2020 - Research and Innovation program - under grant agreement no.~952165. K.N. and A.R. are also grateful for computational resources from the facilities of Research Center for Advanced Computing Infrastructure at Japan Advanced Institute of Science and Technology (JAIST). K.N. acknowledges a support from the JSPS Overseas Research Fellowships, that from Grant-in-Aid for Early-Career Scientists Grant Number JP21K17752, and that from Grant-in-Aid for Scientific Research(C) Grant Number JP21K03400. A.R. gratefully acknowledges the financial support from the MEXT (Monbukagakusho) scholarship. S.S. acknowledges a

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Presenters

  • Kosuke Nakano

    • Condensed Matter Theory group, SISSA

Authors

  • Kosuke Nakano

    • Condensed Matter Theory group, SISSA

  • Abhishek Raghav

    • School of Information Science, JAIST

  • Sandro Sorella

    • International School for Advanced Studies
    • Condensed Matter Theory group, SISSA