Construction of transferable spherically-averaged electron potentials

TL;DR

The paper introduces a new method for constructing approximate effective electron potentials in density-functional theory, simplifying calculations for complex systems by interpolating reference potentials, with successful applications to silicon and aluminum structures.

Contribution

A novel scheme for building transferable electron potentials using reference systems and interpolation, enhancing efficiency in density-functional calculations.

Findings

Excellent agreement with self-consistent potentials for silicon and aluminum.

Effective potential energy shifts can be directly estimated from atom-based densities.

Method simplifies calculations in atomic-sphere and muffin-tin approximations.

Abstract

A new scheme for constructing approximate effective electron potentials within density-functional theory is proposed. The scheme consists of calculating the effective potential for a series of reference systems, and then using these potentials to construct the potential of a general system. To make contact to the reference system the neutral-sphere radius of each atom is used. The scheme can simplify calculations with partial wave methods in the atomic-sphere or muffin-tin approximation, since potential parameters can be precalculated and then for a general system obtained through simple interpolation formulas. We have applied the scheme to construct electron potentials of phonons, surfaces, and different crystal structures of silicon and aluminum atoms, and found excellent agreement with the self-consistent effective potential. By using an approximate total electron density obtained from a superposition of atom-based densities, the energy zero of the corresponding effective potential can be found and the energy shifts in the mean potential between inequivalent atoms can therefore be directly estimated. This approach is shown to work well for surfaces and phonons of silicon.