Simple and accurate exchange energy for density functional theory

Abstract

A non-empirical exchange functional based on an interpolation between two limits of electron density: slowly varying limit and asymptotic limit, is proposed. In the slowly varying limit, we follow the study by Kleinman in 1984 which considered the response of a free-electron gas to an external periodic potential, but further assume that the perturbing potential also induces Bragg diffraction of the Fermi electrons. The interpolation function is motivated by the exact exchange functional of a hydrogen atom. Combined with our recently proposed correlation functional, tests on 56 small molecules show that, for the first-row molecules, the exchange-correlation combo predicts the total energies four times more accurate than presently available Quantum Monte Carlo results. For the second-row molecules, errors of the core electrons exchange energies can be corrected, leading to the most accurate molecular total energy predictions to date despite minimal computational efforts. The calculated bond energies, zero point energies, and dipole moments are also presented.

1) added derivation of mu value 2) add Quantum Monte Carlo results from Ref.7 for comparisons 3) add total energies, bond energies, dipole moments, and zero point energies predictions

References in corpus (4)

• Continuum variational and diffusion quantum Monte Carlo calculations
• An assessment of initial guesses for self-consistent field calculations. Superposition of Atomic Potentials: simple yet efficient
• Energies of the first row atoms from quantum Monte Carlo
• Understanding electron correlation energy through density functional theory

Cited by in corpus (6)

• Benchmarking magnetizabilities with recent density functionals
• An assessment of initial guesses for self-consistent field calculations. Superposition of Atomic Potentials: simple yet efficient
• CIDER: An Expressive, Nonlocal Feature Set for Machine Learning Density Functionals with Exact Constraints
• Nonlocal Machine-Learned Exchange Functional for Molecules and Solids
• Understanding electron correlation energy through density functional theory
• Density functional benchmark for quadruple hydrogen bonds