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Hiroya Nitta

Publications and source records attributed to Hiroya Nitta.

2 recordsLinked to original sources

Omics-scale polymer computational database transferable to real-world artificial intelligence applications

Developing large-scale foundational datasets is a critical milestone in advancing artificial intelligence (AI)-driven scientific innovation. However, unlike AI-mature fields such as natural language processing, materials science, particularly polymer research, has significantly lagged in developing extensive open datasets. This lag is primarily due to the high costs of polymer synthesis and property measurements, along with the vastness and complexity of the chemical space. This study presents PolyOmics, an omics-scale computational database generated through fully automated molecular dynamics simulation pipelines that provide diverse physical properties for over $10^5$ polymeric materials. The PolyOmics database is collaboratively developed by approximately 260 researchers from 48 institutions to bridge the gap between academia and industry. Machine learning models pretrained on PolyOmics can be efficiently fine-tuned for a wide range of real-world downstream tasks, even when only limited experimental data are available. Notably, the generalisation capability of these simulation-to-real transfer models improve significantly as the size of the PolyOmics database increases, exhibiting power-law scaling. The emergence of scaling laws supports the "more is better" principle, highlighting the significance of ultralarge-scale computational materials data for improving real-world prediction performance. This unprecedented omics-scale database reveals vast unexplored regions of polymer materials, providing a foundation for AI-driven polymer science.

physics.chem-ph

Graph theoretical approach to evaluate molecular interactions in crystal

We have applied the graph theory to estimation of interactions between electronic excitations in molecular crystals. Intramolecular and intermolecular excitations have been considered. The intermolecular interactions contain molecular integrals extended over two or three molecules, which we have called dimer or trimer. The intermolecular interactions, such as π-πstacking, is regarded as connections between neighboring molecules. To take up all dimers and trimers in molecular crystal, we have treated the connections between molecules as edges of a graph. The adjacency matrix of the graph and related quantity are utilized to count all dimers and trimers systematically. The absorption spectrum of TiOPc crystal in which we have defined three types of intermolecular excitations is presented.

physics.chem-ph