A local-density approximation for the exchange energy functional for excited states : the band gap problem

TL;DR

This paper introduces a local-density approximation-based excited states DFT method to accurately compute band gaps in semiconductors and insulators, closely matching experimental data.

Contribution

It proposes a simple LDA-like exchange-correlation functional for excited states, improving band gap predictions in DFT calculations.

Findings

The method yields band gap results very close to experimental values.

Using a linear muffin-tin potential simplifies solving the Kohn-Sham equations.

The approach enhances the accuracy of excited state calculations in materials.

Abstract

We present excited states density functional theory (DFT) to calculate band gap for semiconductors and insulators. For the excited states exchange-correlation functional, we use a simple local density approximation (LDA) like functional and it gives the result which is very closed to experimental results. The linear muffin-tin potential is used to solve the self consistent Kohn-Sham equation