XtalOpt: Multi-objective Evolutionary Search for Novel Functional Materials

Workflow of the XtalOpt MOES (Multi-Objective Evolutionary Search) algorithm. After producing the initial set of structures, local relaxations can be performed via various first-principles approaches or by using interatomic potentials. The locally optimized structures are then passed on to external code(s) introduced by the user for calculating desired properties (a few are shown as examples). Subsequently, the fitness function is evaluated for all structures and the parent pool is selected accordingly. New structures are generated by applying various evolutionary operations to the structures chosen from the parent pool.
Workflow of the XtalOpt MOES (Multi-Objective Evolutionary Search) algorithm. After producing the initial set of structures, local relaxations can be performed via various first-principles approaches or by using interatomic potentials. The locally optimized structures are then passed on to external code(s) introduced by the user for calculating desired properties (a few are shown as examples). Subsequently, the fitness function is evaluated for all structures and the parent pool is selected accordingly. New structures are generated by applying various evolutionary operations to the structures chosen from the parent pool.

Version 13 of XtalOpt, an evolutionary algorithm for crystal structure prediction, is now available for download from the CPC program library or the XtalOpt website, https://xtalopt.github.io. In the new version of the XtalOpt code, a general platform for multi-objective global optimization is implemented.

This functionality is designed to facilitate the search for (meta)stable phases of functional materials through minimization of the enthalpy of a crystalline system coupled with the simultaneous optimization of any desired properties that are specified by the user. The code is also able to perform a constrained search by filtering the parent pool of structures based on a user-specified feature, while optimizing multiple objectives.

Here, the implementation and various technical details are presented, and a brief overview is presented of additional improvements that have been introduced in the new version of XtalOpt.

Designing Materials to Revolutionize and Engineer our Future (DMREF)