A chemical bonding based descriptor for predicting the impact of quantum nuclear and anharmonic effects on hydrogen-based superconductors

TL;DR

This paper introduces a new bonding-based descriptor to predict how quantum nuclear and anharmonic effects influence the stability and superconducting properties of hydrogen-based materials, addressing a key challenge in materials science.

Contribution

The study proposes an integrated crystal orbital bonding index (iCOBI) descriptor to forecast the impact of quantum nuclear effects on crystal stability and superconductivity.

Findings

Symmetric bonding environments confer greater structural resilience to QNEs.

Asymmetric bonding environments are more susceptible to QNE-induced changes.

Structures with asymmetric bonds can exhibit enhanced superconducting critical temperatures.

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 a descriptor, based upon the integrated crystal orbital bonding index (iCOBI), 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.