Ryotaro project

Hello world, I'm Ryotaro Koshoji.

I'm a project researcher in The Institute for Solid State Physics (ISSP), The University of Tokyo. I work on developing mathematical crystal chemistry which is a formal theory for crystal structure prediction by generalized disjunctive programming (GDP) based on inorganic structural chemistry. I will predict most of possible ionic crystal structures owing to the overwhelming to speed to design prototypes of crystal structures. Besides, I'm exploring new numerical techniques to evaluate functionalities of chemical compounds with small computations. My major is mathematical crystal chemistry, density functional methods, theoretical physics, and solid-state chemistry.

Education

  • Mar. 2019, B. Phys., Department of Physics, The University of Tokyo
  • Mar. 2021, M. Phys., Department of Physics, The University of Tokyo
  • Mar. 2024, D. Phys., Department of Physics, The University of Tokyo

(Thesis supervisor: Prof. Taisuke Ozaki.)

Professional experience

  • Apr. 2025 ~ present, Project researcher, The Institute for Solid State Physics, The University of Tokyo
  • Apr. 2024 ~ Mar. 2025, Researcher, The National Institute of Advanced Industrial Science and Technology
  • Apr. 2022 ~ Mar. 2024, Research fellowships for Young Scientists (DC2), The University of Tokyo

Invited talks

  • Jun. 2026, "A formal theory for crystal structure prediction by generalized disjunctive programming", D2MatE project meeting, Institute of Science Tokyo, online, Japan
  • Sep. 2025, "Mathematical crystal chemistry: Mathematical formulation of inorganic structural chemistry to Predict and analyze crystal structures of oxides", D2MatE project meeting, Tokyo Institute of Technology, online, Japan
  • Jun. 2025, "Mathematical crystal chemistry", Solid State Chemistry Forum, The University of Tokyo, Chiba, Japan
  • Jun. 2024, "Mathematical crystal chemistry", DxMT project meeting, Tokyo Institute of Technology, online, Japan
  • Feb. 2024, "Crystal structure prediction based on the principle of densest packings", The Society of Boron, Borides and Related Materials of Japan, The University of Tokyo, Chiba, Japan
  • May. 2023, "Exhaustive search for densest sphere packings and quaternary hydrides", ISSP Workshop, The University of Tokyo, Chiba, Japan

Funding (Principal investigator)

  • Apr. 2026 ~ Mar. 2029, "Mathematical crystal chemistry: Mixed-integer nonlinear programming for crystal structure prediction", Nippon Sheet Glass Foundation for Materials Science and Engineering
  • Apr. 2025 ~ Mar. 2026, "Mathematical proramming for optimal control of ceramics processing", The Kazuchika Okura Memorial Foundation

Funding (Co-investigator)

  • Apr. 2026 ~ Mar. 2029, "Creation of High-Tc Superconductors and Novel Quantum Magnets Based on Anionic Transition-Metal Compounds", Grant-in-Aid for Scientific Research (A) (26H02231)