An efficient method for the Quantum Monte Carlo evaluation of the static density-response function of a many-electron system

TL;DR

This paper presents an efficient quantum Monte Carlo method to evaluate the static density-response function of many-electron systems, improving accuracy and handling nodal effects effectively.

Contribution

It introduces a new approach based on Hellmann-Feynman operator sampling for calculating the density-response function in diffusion Monte Carlo.

Findings

Correlation is correctly described by the method.

The effect of the nodes can be effectively managed.

The method shows improved efficiency in calculations.

Abstract

In a recent Letter we introduced Hellmann-Feynman operator sampling in diffusion Monte Carlo calculations. Here we derive, by evaluating the second derivative of the total energy, an efficient method for the calculation of the static density-response function of a many-electron system. Our analysis of the effect of the nodes suggests that correlation is described correctly and we find that the effect of the nodes can be dealt with.