Computing energy barriers for rare events from hybrid quantum/classical simulations through the virtual work principle

TL;DR

This paper introduces a novel method based on the virtual work principle within a modified nudged elastic band algorithm to compute energy barriers in hybrid quantum/classical simulations, enabling first-of-its-kind ab initio calculations for dislocation and fracture phenomena.

Contribution

It presents a general approach to calculate energy barriers in hybrid simulations where total energy is undefined, expanding the scope of ab initio modeling for materials.

Findings

First ab initio calculations of kink formation energy in molybdenum dislocations

Lattice trapping barriers to brittle fracture in silicon quantified

Method overcomes limitations of non-local electronic effects in energy calculations

Abstract

Hybrid quantum/classical techniques can flexibly couple ab initio simulations to an empirical or elastic medium to model materials systems that cannot be contained in small periodic supercells. However, due to electronic non-locality a total energy cannot be defined, meaning energy barriers cannot be calculated. We provide a general solution using the principle of virtual work in a modified nudged elastic band algorithm. Our method enables the first ab initio calculations of the kink formation energy for <100> edge dislocations in molybdenum and lattice trapping barriers to brittle fracture in silicon.