Evolutionary Metadynamics: a Novel Method to Predict Crystal Structures

TL;DR

This paper introduces a new crystal structure prediction method combining metadynamics and evolutionary algorithms, efficiently identifying stable and metastable states and providing insights into phase transition mechanisms.

Contribution

It presents a novel evolutionary metadynamics approach that improves crystal structure prediction by integrating collective variables and evolutionary operators.

Findings

Successfully predicted structures of Al₂SiO₅, SiO₂, MgSiO₃, and carbon.

Able to find both ground and metastable states.

Provides insights into phase transition mechanisms.

Abstract

A novel method for crystal structure prediction, based on metadynamics and evolutionary algorithms, is presented here. This technique can be used to produce efficiently both the ground state and metastable states easily reachable from a reasonable initial structure. We use the cell shape as collective variable and evolutionary variation operators developed in the context of the USPEX method [Oganov, Glass, \textit{J. Chem. Phys.}, 2006, \textbf{124}, 244704; Lyakhov \textit{et al., Comp. Phys. Comm.}, 2010, \textbf{181}, 1623; Oganov \textit{et al., Acc. Chem. Res.}, 2011, \textbf{44}, 227] to equilibrate the system as a function of the collective variables. We illustrate how this approach helps one to find stable and metastable states for Al$_2$SiO$_5$, SiO$_2$, MgSiO$_3$, and carbon. Apart from predicting crystal structures, the new method can also provide insight into mechanisms of phase transitions.