Director of Quantum Chemistry Research Institute, Kyoto, Japan.

Email: h.nakatsuji@qcri.or.jp

WWW: http://quanta.synchem.kyoto-u.ac.jp

Physical Chemistry Award of the Chemical Society of Japan (1991).

Editor of Journal of Computational Chemistry

Author of:

About 300 research papers in theoretical chemistry and physics.

Important Contributions:

Theory of Excited Molecular Electronic Structure: SAC-CI method (1978) is useful for studying 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, geometries and reactions of excited states, surface photochemistry, and molecular biology, and was implemented in Gaussian 03.

Theory for the Direct Determination of Density Matrix: Density equation (1976) which is equivalent to the Schrödinger equation in the density-matrix space was solved for real molecules using only density matrix (1996). Variational principle for density matrix was formulated using positive definite algorithm (2001).

Structure of the Exact Wave Function and the Method of Solving the Schrödinger Equation: Description of the exact wave function with singles-and-doubles or even smaller number of variables is shown possible, by providing iterative CI (ICI) and extended (or extreme) coupled cluster formalisms (2000-2003).

Force Concept for Molecular Geometry: Based on the electrostatic (Hellmann-Feynman) theorem, a conceptual force model for molecular geometry was developed (1973-74) and shown to be more useful than the VSEPR theory and the Walsh model. Common behaviors of molecular electron density under nuclear rearrangement process (like chemical reaction) were characterized.

Dipped Adcluster Model (DAM) for Surface-Molecule Reactions: DAM (1987) is a simple theoretical model of the electronic structure of the adsorbate on a metal surface and includes the effects of electron transfer and image force due to the bulk metal. DAM has been of crucial importance for clarifying the mechanisms of various catalytic reactions. It also describes the surface photochemistry of adsorbates in combination with the SAC-CI method.

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).