Hellman-Feynman operator sampling in Diffusion Monte Carlo calculations
Other Condensed Matter
2009-11-13 v1
Abstract
Diffusion Monte Carlo (DMC) calculations typically yield highly accurate results in solid-state and quantum-chemical calculations. However, operators that do not commute with the Hamiltonian are at best sampled correctly up to second order in the error of the underlying trial wavefunction, once simple corrections have been applied. This error is of the same order as that for the energy in variational calculations. Operators that suffer from these problems include potential energies and the density. This paper presents a new method, based on the Hellman-Feynman theorem, for the correct DMC sampling of all operators diagonal in real space. Our method is easy to implement in any standard DMC code.
Cite
@article{arxiv.0708.0542,
title = {Hellman-Feynman operator sampling in Diffusion Monte Carlo calculations},
author = {R. Gaudoin and J. M. Pitarke},
journal= {arXiv preprint arXiv:0708.0542},
year = {2009}
}