Fractional charge by fixed-node diffusion Monte Carlo

Abstract

Fixed-node diffusion Monte Carlo (FNDMC) is a stochastic quantum many-body method that has a great potential in electronic structure theory. We examine how FNDMC satisfies exact constraints, linearity and derivative discontinuity of total energy $E(N)$ vs. fractional electron number $N$, if combined with mean-field trial wave functions that miss such features. H and Cl atoms with fractional charge reveal that FNDMC is well able to restore the piecewise linearity of $E(N)$. The method uses ensemble and projector ingredients to achieve the correct charge localization. Water-solvated Cl${}^{-}$ complex illustrates superior performance of FNDMC for charged noncovalent systems.

References in corpus (7)

• QMCPACK : An open source ab initio Quantum Monte Carlo package for the electronic structure of atoms, molecules, and solids
• The discontinuous nature of the exchange-correlation functional -- critical for strongly correlated systems
• Beyond the locality approximation in the standard diffusion Monte Carlo method
• Applications of quantum Monte Carlo methods in condensed systems
• Multi-Determinant Wave-functions in Quantum Monte Carlo
• Accurate barrier heights using diffusion Monte Carlo
• Qualitative breakdown of the unrestricted Hartree-Fock energy

Cited by in corpus (1)

• Quantum Monte Carlo Benchmarking of Molecular Adsorption on Graphene-Supported Single Pt Atom