High-Level Correlated Approach to the Jellium Surface Energy, Without Uniform-Electron-Gas Input

TL;DR

This paper uses a high-level correlated approach, ISTLS, to accurately determine the surface energy of simple metals, confirming the reliability of density functional methods and aligning with recent DMC results.

Contribution

It demonstrates that the ISTLS method provides reliable surface energy estimates, resolving discrepancies between density functional and high-level correlated calculations.

Findings

ISTLS results agree with revised DMC values.

Density functionals are reliable for surface energy calculations.

Validates use of uniform-gas-based kernels in time-dependent DFT.

Abstract

We resolve the long-standing controversy over the surface energy of simple metals: Density functional methods that require uniform-electron-gas input agree with each other at many levels of sophistication, but not with high-level correlated calculations like Fermi Hypernetted Chain and Diffusion Monte Carlo (DMC) that predict the uniform-gas correlation energy. Here we apply a very high-level correlated approach, the inhomogeneous Singwi-Tosi-Land-Sj\"olander (ISTLS) method, and find that the density functionals are indeed reliable (because the surface energy is "bulk-like"). ISTLS values are close to recently-revised DMC values. Our work also vindicates the previously-disputed use of uniform-gas-based nonlocal kernels in time-dependent density functional theory.