Atomic Decompositions of Periodic Electronic-Structure Simulations

TL;DR

This paper introduces a novel atomic decomposition method for periodic electronic-structure simulations using localized Gaussian orbitals, improving interpretability of local features in crystalline systems.

Contribution

The authors develop a new theory for partitioning periodic systems into atomic contributions at the DFT level, utilizing localized Gaussian orbitals for clearer physical insights.

Findings

Decomposed cohesive energies align with expected charge polarization.

Method provides more intuitive atomic insights than traditional basis-based approaches.

Applicable to molecular polymers and crystalline polymorphs.

Abstract

We present a new theory for partitioning simulations of periodic and solid-state systems into physically sound atomic contributions at the level of Kohn-Sham density functional theory. Our theory is based on spatially localized linear combinations of crystalline Gaussian-type orbitals and, as such, capable of exposing local features within periodic electronic structures in a more intuitive and robust manner than alternatives based on the spatial distribution of atomic basis functions alone. Early decomposed cohesive energies of both molecular polymers and different crystalline polymorphs demonstrate how the atomic properties yielded by our theory convincingly align with the expected charge polarization in these systems, also whenever partial charges and Madelung energies may lend themselves somewhat ambiguous to interpretation.