Exploring the high-pressure materials genome

TL;DR

This paper introduces a hybrid computational framework that combines data-driven databases with simple enthalpy approximations to predict high-pressure phases and guide materials discovery under extreme conditions.

Contribution

It presents a novel approach integrating large materials databases with a linear enthalpy approximation to efficiently explore high-pressure material phases.

Findings

Explains occurrence of natural phases not stable at ambient conditions.

Estimates pressures for metastable phases to become stable.

Guides discovery of new high-pressure stable phases.

Abstract

A thorough in situ characterization of materials at extreme conditions is challenging, and computational tools such as crystal structural search methods in combination with ab initio calculations are widely used to guide experiments by predicting the composition, structure, and properties of high-pressure compounds. However, such techniques are usually computationally expensive and not suitable for large-scale combinatorial exploration. On the other hand, data-driven computational approaches using large materials databases are useful for the analysis of energetics and stability of hundreds of thousands of compounds, but their utility for materials discovery is largely limited to idealized conditions of zero temperature and pressure. Here, we present a novel framework combining the two computational approaches, using a simple linear approximation to the enthalpy of a compound in conjunction with ambient-conditions data currently available in high-throughput databases of calculated materials properties. We demonstrate its utility by explaining the occurrence of phases in nature that are not ground states at ambient conditions and estimating the pressures at which such ambient-metastable phases become thermodynamically accessible, as well as guiding the exploration of ambient-immiscible binary systems via sophisticated structural search methods to discover new stable high-pressure phases.