# Assessment of long-range-corrected exchange-correlation kernels for solids: accurate exciton binding energies via an empirically scaled Bootstrap kernel

## TL;DR

This paper evaluates various long-range-corrected exchange-correlation kernels in time-dependent density-functional theory for solids, identifying limitations and proposing an empirically scaled Bootstrap kernel that accurately predicts exciton binding energies across different materials.

## Contribution

The paper introduces a simple, universal, empirically scaled Bootstrap kernel that improves exciton binding energy predictions in solids with low computational cost.

## Key findings

- No existing LRC kernel accurately predicts both spectra and binding energies.
- The scaled Bootstrap kernel provides accurate exciton binding energies for all tested materials.
- The study highlights the limitations of current kernels in simultaneously modeling optical spectra and exciton binding energies.

## Abstract

In time-dependent density-functional theory, a family of exchange-correlation kernels, known as long-range-corrected (LRC) kernels, have shown promise in the calculation of excitonic effects in solids. We perform a systematic assessment of existing static LRC kernels (empirical LRC, Bootstrap, and jellium-with-a-gap model) for a range of semiconductors and insulators, focusing on optical spectra and exciton binding energies. We find that no LRC kernel is capable of simultaneously producing good optical spectra and quantitatively accurate exciton binding energies for both semiconductors and insulators. We propose a simple and universal, empirically scaled Bootstrap kernel which yields accurate exciton binding energies for all materials under consideration, with low computational cost.