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 by 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 high-pressure phases.
- Received 20 March 2018
- Revised 23 September 2018
DOI:https://doi.org/10.1103/PhysRevX.8.041021
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.
Published by the American Physical Society
Physics Subject Headings (PhySH)
Popular Summary
Understanding how materials behave under extreme pressure has a range of benefits, from the design of exotic materials to a better understanding of planetary interiors. Researchers typically use computational tools to guide experiments by predicting composition, structure, and properties of materials under pressure. However, these techniques are computationally expensive. Data-driven approaches using large databases of materials are useful for analyzing 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 these two approaches to provide an efficient assessment of the thermodynamic stability of materials at nonzero pressure.
Our approach uses a simple linear approximation to the enthalpy of a compound in conjunction with data on ambient conditions currently available in high-throughput databases of calculated materials properties. We find that we can readily explain the occurrence of phases in nature that are not ground states at ambient conditions. In conjunction with crystal structure search schemes, our approach effectively predicts new high-pressure phases that can be realized with existing high-pressure experimental methods.
This framework paves a route toward robust exploration of the entire high-pressure materials genome based on emerging materials big data, leading to accelerated materials discovery at nonambient pressures.