Ontologies in Computational Materials Science

With the tremendous increase in the amount of data in materials science, new ways to store and annotate data are necessary to successfully implement the FAIR principles -- and to do good and new science efficiently. Consequently, ontologies have been of increasing interest as they serve as an advanced level of annotation enabling the semantic linking of data even across domains. The Novel-Materials Discovery (NOMAD) Repository is the largest database in materials science and provides a normalized, source-independent form of these data in the NOMAD Archive using the NOMAD Metainfo [1] as metadata schema. The NOMAD Metainfo includes a number of relations between concepts and therefore already goes beyond a metadata catalogue. We advanced it to an ontology and extended it to increase semantics based on the European Materials and Modeling Ontology (EMMO). Furthermore, within the NOMAD ecosystem, we created an ontology collection covering materials structures and properties and their semantic relations. We demonstrate how this enables connecting multiple sources of knowledge and semantic searches. The search for a better solar cell material is used as a first application example.
[1] L. M. Ghiringhelli et al., npj Comput. Mater. 3, 46 (2017).