Orbital-dependent backflow wave functions for real-space quantum Monte Carlo

TL;DR

This paper introduces an orbital-dependent backflow wave function for real-space Quantum Monte Carlo, improving correlation energy calculations in electronic structure with comparable computational cost to simpler methods.

Contribution

The paper develops and applies an orbital-dependent backflow wave function that enhances correlation energy accuracy in quantum Monte Carlo simulations.

Findings

Achieves systematic gain in correlation energy over single determinant wave functions.

Performance is competitive with the best existing trial wave functions.

Computational cost remains comparable to simple backflow calculations.

Abstract

We present and motivate an efficient way to include orbital dependent many--body correlations in trial wave function of real--space Quantum Monte Carlo methods for use in electronic structure calculations. We apply our new orbital--dependent backflow wave function to calculate ground state energies of the first row atoms using variational and diffusion Monte Carlo methods. The systematic overall gain of correlation energy with respect to single determinant Jastrow-Slater wave functions is competitive with the best single determinant trial wave functions currently available. The computational cost per Monte Carlo step is comparable to that of simple backflow calculations.