In order to find the equilibrium geometries of molecules and solids and to perform ab initio molecular dynamics, it is necessary to calculate the forces on the nuclei. We present a correlated sampling method to efficiently calculate numerical forces and potential energy surfaces in diffusion Monte Carlo. It employs a novel coordinate transformation, earlier used in variational Monte Carlo, to greatly reduce the statistical error. Results are presented for first-row diatomic molecules.
@article{arxiv.cond-mat/9911326,
title = {Correlated sampling in quantum Monte Carlo: a route to forces},
author = {Claudia Filippi and C. J. Umrigar},
journal= {arXiv preprint arXiv:cond-mat/9911326},
year = {2009}
}