Director: Hiroshi Nakatsuji
- General Methods of Solving the Schrödinger and Dirac Equations were proposed (2000-2007). In his theory, the Hamiltonian of the system paves the way to its exact ground and excited wave functions, producing the complement functions that span the potentially exact wave functions. Variational calculations give super accurate results and local Schrödinger equation (LSE) method provides a general integral-free method that is applicable to any atoms and molecules. See, Acc. Chem. Res. 45(9), 1480-1490 (2012) for a review.
- SAC-CI Theory for Molecular Excited and Ionized States (1978) is useful to study singlet-to-septet ground and excited states of organic and inorganic molecular systems and the energy gradient of each state. It has been applied to fine spectroscopy, photobiology, surface photochemistry, and giant molecular systems. This program is implemented in Gaussian.
- Dipped Adcluster Model (DAM) for Surface-Molecule Interactions and Reactions (1987) is a theoretical model for chemisorptions and catalytic reactions on a metal surface. It includes the effects of bulk metal like electron transfer and image force. DAM has been useful to clarify surface chemistry like electron harpooning and transfer, olefin epoxidation reactions on Ag surface, etc.
- Theory for the Direct Determination of Density Matrix: Density equation that is equivalent to the Schrödinger equation in the density-matrix space was presented (1976) and solved for real molecules (1996). Variational principle for 2-density matrices was formulated using the positive definite algorithm (2001).
- Intuitive Force Concept for Molecular Geometry and Chemical Reaction was developed (1973) based on the electrostatic (Hellmann-Feynman) theorem. It is more useful than the VSEPR theory and the Walsh model. Electron-cloud preceding (1974) was shown to be a common behavior in the course of the chemical reaction.
- Electronic Mechanism and Relativistic Effect in NMR Chemical Shifts: Electronic mechanism of the metal chemical shift is an intrinsic property of the resonant nucleus, characterized by its position in the periodic table (1984-1993). Relativistic effects are of crucial importance for molecules including heavy elements (1995-2003) even when the resonant nucleus is light.
Research Theme :
I am developing the Giant SAC-CI method, which is an extention of the SAC-CI methodology to giant molecular systmes. This development makes it possible to apply to giant molecular systems, which are difficult to calculate using the SAC-CI method. Now I am studying the helical structure of DNA using the SAC-CI and Giant SAC-CI methods. I am planning to develop the SAC-CI and Giant SAC-CI methods and to clarify and predict chemical phenomena involving photo and excited states.
Recently, the method converging to the exact solution of the Schrödinger and Dirac equations was proposed. Based on the extremely accurate solutions, our purpose is to realize predictive quantum chemistry for atomic and molecular science.
Yusaku I. Kurokawa
Research Theme: General method to solve the Schrödinger and Dirac equations.
Ryoichi Fukuda (Institute for Molecular Science, Research Center for Computational Science)
Masahiro Ehara (Institute for Molecular Science)
Jun-ya Hasegawa (Catalysis Research Center, Hokkaido Univ.)
Takamasa Momose (The University of British Columbia, Canada)
Roberto Cammi (University of Parma, Italy)
Hiroshi Sugiyama (Graduate School of Science, Kyoto University)
Takehiko Wada (Institute of Multidisciplinary Research for Advanced Materials, Tohoku Univ.)