Inhomogeneous backflow transformations in quantum Monte Carlo calculations

TL;DR

This paper introduces an inhomogeneous backflow transformation for many-particle wave functions, demonstrating its effectiveness in improving correlation energy retrieval and wave function quality in quantum Monte Carlo calculations for various systems.

Contribution

The paper presents a novel inhomogeneous backflow transformation method and evaluates its impact on quantum Monte Carlo energies and wave function accuracy.

Findings

Inhomogeneous backflow increases correlation energy retrieval in VMC and DMC.

Backflow transformations significantly improve wave function nodal surfaces.

The method's computational cost is analyzed and found manageable.

Abstract

An inhomogeneous backflow transformation for many-particle wave functions is presented and applied to electrons in atoms, molecules, and solids. We report variational and diffusion quantum Monte Carlo VMC and DMC energies for various systems and study the computational cost of using backflow wave functions. We find that inhomogeneous backflow transformations can provide a substantial increase in the amount of correlation energy retrieved within VMC and DMC calculations. The backflow transformations significantly improve the wave functions and their nodal surfaces.