All-electron density functional theory and time-dependent density functional theory with high-order finite elements

TL;DR

This paper introduces an all-electron computational method using high-order finite elements for density functional theory and time-dependent density functional theory, enabling accurate core and valence state calculations without pseudopotentials.

Contribution

The method employs a novel mesh generation scheme that combines structured atomic meshes with unstructured molecular meshes for highly nonuniform discretization, eliminating the need for pseudopotentials.

Findings

Accurate representation of core and valence states without pseudopotentials.

Ability to use large simulation cells to avoid boundary effects.

Flexible mesh generation for complex molecular geometries.

Abstract

We present for static density functional theory and time-dependent density functional theory calculations an all-electron method which employs high-order hierarchical finite element bases. Our mesh generation scheme, in which structured atomic meshes are merged to an unstructured molecular mesh, allows a highly nonuniform discretization of the space. Thus it is possible to represent the core and valence states using the same discretization scheme, i.e., no pseudopotentials or similar treatments are required. The nonuniform discretization also allows the use of large simulation cells, and therefore avoids any boundary effects.