Quantum Monte Carlo study of the first-row atoms and ions

TL;DR

This paper uses advanced Quantum Monte Carlo methods with sophisticated trial wave functions to accurately calculate energies, ionization potentials, and relativistic effects for first-row atoms and ions, achieving chemical accuracy.

Contribution

It presents the first high-accuracy Quantum Monte Carlo calculations of first-row atoms and ions, including relativistic corrections and expectation values.

Findings

Recovered over 98% of correlation energy at VMC level

Achieved over 99% of correlation energy at DMC level

Obtained ionization potentials with chemical accuracy

Abstract

Quantum Monte Carlo calculations of the first-row atoms Li-Ne and their singly-positively-charged ions are reported. Multi-determinant-Jastrow-backflow trial wave functions are used which recover more than 98% of the correlation energy at the Variational Monte Carlo (VMC) level and more than 99% of the correlation energy at the Diffusion Monte Carlo (DMC) level for both the atoms and ions. We obtain the first ionization potentials to chemical accuracy. We also report scalar relativistic corrections to the energies, mass-polarization terms, and one- and two-electron expectation values.