Energies of the first row atoms from quantum Monte Carlo

TL;DR

This paper reports all-electron quantum Monte Carlo calculations of the ground state energies of first row atoms, achieving high accuracy in correlation energy recovery with various trial wavefunctions.

Contribution

It introduces and compares multiple types of trial wavefunctions in quantum Monte Carlo calculations for first row atoms, demonstrating high accuracy in energy estimates.

Findings

Recovered over 99% of correlation energy for Li to Ne

Achieved 97-98% correlation energy recovery for O and F

Demonstrated effectiveness of backflow transformations in wavefunctions

Abstract

All-electron variational and diffusion quantum Monte Carlo calculations of the ground state energies of the first row atoms (Li to Ne) are reported. We use trial wavefunctions of four types: single determinant Slater-Jastrow wavefunctions; multi-determinant Slater-Jastrow wavefunctions; single determinant Slater-Jastrow wavefunctions with backflow transformations; multi-determinant Slater-Jastrow wavefunctions with backflow transformations. At the diffusion quantum Monte Carlo level and using our best trial wavefunctions we recover 99% or more of the correlation energy for Li, Be, B, C, N, and Ne, 97% for O, and 98% for F.