# A chemical bonding based descriptor for predicting the role of anharmonicity induced by quantum nuclear effects in hydride superconductors

## TL;DR

This paper introduces new descriptors to predict how quantum nuclear effects influence superconductivity and crystal stability in hydride materials.

## Contribution

The paper introduces two novel descriptors based on chemical bonding to predict the impact of quantum nuclear effects on superconductivity.

## Key findings

- Symmetric bonding environments show greater resilience to structural changes from quantum nuclear effects.
- Asymmetric bonding environments lead to structural alterations and higher superconducting critical temperatures.
- The descriptors help predict dynamic stability and superconducting properties influenced by quantum nuclear effects.

## Abstract

Quantum nuclear effects (QNEs) can significantly alter a material’s crystal structure and phonon spectra, impacting properties such as thermal conductivity and superconductivity. However, predicting a priori whether these effects will enhance or suppress superconductivity, or destabilize a structure, remains a grand challenge. Herein, we address this unresolved problem by introducing two possible descriptors, based upon the integrated crystal orbital bonding index (iCOBI) or the bond valence function, to predict the influence of QNEs on a crystal lattice’s dynamic stability, phonon spectra and superconducting properties. We find that structures with atoms in symmetric chemical bonding environments exhibit greater resilience to structural perturbations induced by QNEs, while those with atoms in asymmetric bonding environments are more susceptible to structural alterations, resulting in enhanced superconducting critical temperatures.