MIT Department of Chemistry
Cambridge, MA 02139
mit.edu email: tsuchimochi
Year joined: 2012
|2011||PhD in Chemistry||Rice University||Advisor: Gustavo Scuseria|
|2007||BS in Chemistry||Waseda University|
Density Matrix Embedding
Density Matrix Embedding Theory (DMET), recently developed by Knizia and Chan, is a simple but very powerful way of treating strongly correlated systems. This is made possible by mapping the interacting system onto a small impurity-bath model. I am currently working on DMET for excited states.
We are conducting research on the mechanism of the water splitting reaction. The oxygen evolution reaction has the well-known standard potential of 1.23V (vs. NHE), but in order for it to occur, one has to go over the potential energy barriers, which requires application of an additional bias, or overpotential. By using density functional theory (DFT), we are currently seeking for simple procedures which are computationally efficient yet accurate in order to compute thermodynamics lower bounds on overpotentials for the water splitting reaction. We are applying these procedures to relatively small catalytic clusters with a series of transition metals, to be able to help experimental catalytic design.
Restricted Open-shell Kohn-Sham
We are revisiting restricted open-shell Kohn-Sham (ROKS) as a simple self-consistent field (SCF) approach to computing open-shell singlet systems. The Fock operator we derived through the Hirao-Nakatsuji general SCF conditions is variational, and thus can be used for the ROKS gradient straightforwardly. However, in some cases, this variational Fock operator minimizes the energy unreasonably low by maximizing the overlap between the ground state and the target ROKS state. We showed that a small level-shift between open-shell orbitals can avoid this problem, and that the excitation energies and Stokes shifts obtained from ROKS are comparable to those of time-dependent DFT and DeltaSCF.