Our research interest is in the first-principles (FP) computational method both its application to condensed matters and its development. The FP calculation is the method to solve the basic equation, such as Schrödinger equation, without abstracting the target thereby enabling prediction of the material properties. It requires very large computational time and, therefore, it is essentially important to improve the algorithms towards higher accuracy with enhanced efficiency. We do this by utilizing the many-body Green’s function method and the tensor decomposition method and aim at realizing high-accuracy ground state calculation, reliable excited state calculation, and non-equilibrium calculation. We are also interested in the ultrafast chemical reactions and developing a method for the non-Born-Oppenheimer dynamics. Target of our application study is now the fuel-cell reactions, the water splitting and related energy-conversion mechanism, and our fuel-cell simulation has been selected as the priority project of the K-computer.
Development of the effective screening medium method, which has enabled electrocatalytic reaction dynamics simulation at Pt/solution interface.
Development of the nonadiabatic couplings, which has enabled photo-isomerization dynamics of a folmaldimine molecule.
Nonadiabatic couplings from time-dependent density functional theory: Formulation by the Kohn-Sham derivative matrix within density functional perturbation theory: C. Hu, T. Tsukagoshi, O. Sugino and K. Watanabe, Phys. Rev. B87 (2013) 035421.