Bypassing the energy functional in density functional theory: Direct calculation of electronic energies from conditional probability densities

TL;DR

This paper introduces a novel approach called CP-DFT that calculates electronic energies directly from conditional probability densities, overcoming limitations of traditional density functional theory in various challenging scenarios.

Contribution

The paper presents CP-DFT as an alternative to traditional methods, enabling accurate energy calculations without relying on exchange-correlation approximations.

Findings

Accurately computes energies for two-electron ions and hydrogen dimer.

Eliminates self-interaction error for one-electron systems.

Successfully models warm dense matter with classical CP-DFT.

Abstract

Density functional calculations can fail for want of an accurate exchange-correlation approximation. The energy can instead be extracted from a sequence of density functional calculations of conditional probabilities (CP-DFT). Simple CP approximations yield usefully accurate results for two-electron ions, the hydrogen dimer, and the uniform gas at all temperatures. CP-DFT has no self-interaction error for one electron, and correctly dissociates H2, both major challenges. For warm dense matter, classical CP-DFT calculations can overcome the convergence problems of Kohn-Sham DFT.