Naoki Nakatani

Graduate School of Science, Tokyo Metropolitan University
Associate Professor

Research AreasQuantum Chemistry
Participating Group (2020-2021)

Periodic QM/MM Study on the Geometry and Electronic Structure of Soft-Crystals

Periodic QM/MM Method, Soft Crystal, Transition Metal Complex, Density Matrix Renormalization Group, Vapochromism, Mechanochromism

Research Outline

Although quantum chemistry calculations have been a common tool for investigating molecules in gas-phase or liquid-phase, it is still not available for investigating molecules in molecular crystals. In this study, a new theoretical approach is developed based on the periodic QM/MM method in order to accurately compute molecules in crystal-phase. Particularly, it enables to quantitatively investigate non-classical interactions such as metal-metal interaction and/or π-π stacking interaction, which are origins for physical and chemical properties of soft-crystals (vapochromism, mechanochromism, etc.). During this research project, (1) a periodic QM/MM method is extended based on the density matrix renormalization group (DMRG) approach which enables to compute non-classical interactions over unit-cell, (2) crystal packing effect is quantitatively analyzed to investigate influence in geometry of a metal complex in crystal, and (3) the molecular mechanisms of vapochromism and mechanochromism in soft-crystals are theoretically investigated based on our method.

Schematic image of the periodic DMRG-QM/MM method


Academic papers/reviewed


  1. "Theoretical Studies of Reaction Mechanisms for Half-Titanocene-Catalyzed Styrene Polymerization, Ethylene Polymerization, and Styrene-Ethylene Copolymerization: Roles of the Neutral Ti(III) and the Cationic Ti(IV) Species" J. Yi, *N. Nakatani, N. Tomotsu, K. Nomura, M. Hada, Organometallics, 40, 643-653 (2021).
  2. "Transmission Electron Microscopy Study of the Morphology of Ices Composed of H2O, CO2, and CO on Refractory Grains" A. Kouchi, M. Tsuge, T. Hama, Y. Oba, S. Okuzumi, S. Sirono, M. Momose, N. Nakatani, K. Furuya, T. Shimonishi, T. Yamazaki, H. Hidaka, Y. Kimura, K. Murata, K. Fujita, S. Nakatsubo, S. Tachibana, N. Watanabe, Astrophys. J., 918, 45 (2021).

International conferences


  1. "Linear response theory and 2nd-order perturbation theory on the DMRG wavefunction" N. Nakatani (Invited), Norway-Japan symposium on theoretical and experimental chemistry of complex systems (Online, March 15-16, 2022)
  2. "TDDFT studies on the XANES spectra of Ti and V complex catalysts" N. Nakatani (Invited), Japan-Norway Bilateral Symposium from Fundamental Chemistry to Porous Materials: Theory and Experiment (Online, Aug. 20-21, 2020)

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