Laplacian-level density functionals for the exchange-correlation energy of low-dimensional nanostructures

TL;DR

This paper introduces simplified two-dimensional density functionals for low-dimensional nanostructures, improving computational efficiency while maintaining or enhancing accuracy in modeling electron-electron interactions.

Contribution

It develops a simplified meta-GGA density functional approach for 2D systems, reducing orbital dependence and enhancing practical applicability.

Findings

Accurate density functionals for 2D nanostructures

Preserved or improved accuracy in quantum-dot tests

Simplified dependence on electron density and derivatives

Abstract

In modeling low-dimensional electronic nanostructures, the evaluation of the electron-electron interaction is a challenging task. Here we present an accurate and practical density-functional approach to the two-dimensional many-electron problem. In particular, we show that spin-density functionals in the class of meta-generalized-gradient approximations can be greatly simplified by reducing the explicit dependence on the Kohn-Sham orbitals to the dependence on the electron spin density and its spatial derivatives. Tests on various quantum-dot systems show that the overall accuracy is well preserved, if not even improved, by the modifications.