Electronic and magnetic properties of crystals are primarily defined by their electronic band structure — an energy spectrum of electrons motion which stem from their quantum-mechanical properties. Computer calculation of such structures is known to be a non-trivial task which demands large computational resources. Exponential growth of computational power we witness now and high demand for prediction of materials with target properties led to a new way of dealing with quantum materials referred to as materials informatics. This approach places the main effort on performing high-throughput computing and data mining as well as the development of sufficient tools for that. One can call this approach an “aggregate informatics analysis”, where the properties of a single compound are captured approximately and main resource is placed on understanding global trends within the large datasets.
Applications of this informatics-driven approach are wide-ranging and cover, for instance, the search for various functional materials with special electrical, optical and magnetic properties, including the 2016 Nobel Prize-winning topological states of matter, an important building block of a quantum computer. Motivated by this new trend in materials informatics, the Condensed Matter research group at Nordita (a joint KTH and SU institution in Stockholm, Sweden) has developed a web database as a source for data mining projects. The database will facilitate the first-principles investigation of organics and the prediction of organic functional materials given their high potential for industrial applications.
The Organic Materials Database (OMDB) is an electronic structure database for various organic and organometallic materials, freely accessible via a web interface at http://omdb.diracmaterials.org/. The electronic band structures are calculated using density functional theory that is a standard tool in modern materials science. The OMDB web interface allows users to search for materials with specified target properties using non-trivial queries about their electronic structure, including advanced tools for pattern recognition, chemical and physical properties search. More information about the functionality and potential applications of the OMDB database can be found in the article by S. S. Borysov et al, “Organic Materials Database: an Open-Access Online Database for Data Mining”, PLOS ONE 12(2): e0171501 (2017).
The first outcome of the research project was discovery of new organic Dirac materials (EU Research Summer/Autumn 2016) which were reported in two scientific papers by R. M. Geilhufe et al, Phys. Rev. B 95, 041103(R) (2017) and Sci. Rep. 7(1), 7298 (2017). There is also ongoing search for novel materials for organic solar cells, organic metals and semiconductors.
Electronic band structure (left) and density of states (right) of an organic Dirac material (C6H7ClO3). Dirac points are highlighted with green and red dashed circles [R. M. Geilhufe et al, Sci. Rep. 7(1), 7298 (2017)]
Linear dispersion near a high-symmetry point of an organic Dirac material (C6H7ClO3) [R. M. Geilhufe et al, Sci. Rep. 7(1), 7298 (2017)]
The database is supported by the VILLUM Centre of Excellence for Dirac Materials and Nordita. The computational resources are provided by the Max Planck Institute of Microstructure Physics in Halle (Germany) and the Swedish National Infrastructure for Computing (SNIC) at the National Supercomputer Centre at Linköping University.