The BEDT-TTF salts, which have two-dimensional BEDT-TTF and anion layers, have many interesting phsical properties.

beta'-(BEDT-TTF)2X is the Mott insulator at ambient pressure. beta'-(BEDT-TTF)2ICl2 shows superconductivity at pressures, while beta'-(BEDT-TTF)2AuCl2 does not show superconductivity at pressures. They are isostructural materials, but shows other phases. We have clalified the electronic structure at pressures in the first-principles study. Next we studied the phase diagram in the effective model Hamiltonian. The resultant phase diagram shows that beta'-(BEDT-TTF)2ICl2 shows superconductivity, while beta'-(BEDT-TTF)2AuCl2 does not show superconductivity. This originates from the small difference of the warping of the Fermi surfaces.

Theoretical phase diagram of beta'-(BEDT-TTF)ICl2.

alpha-(BEDT-TTF)2I3 is an insulator with charge-disproportionation at ambient pressures. It is metallic at pressures. The conductivity is proportional to the T-square at low temperatures in the metallic phase, and has high mobility. Our calculation clarified the existence of the two-dimensional massless-Dirac cone dispersion at the Fermi level.

massless Dirac cone dispersion in alpha-(BEDT-TTF)2I3.

tutorial of Non-equilibrium Green function method
(pdf
or
html)

This method is applied to the OpenMX code.

(old) explantions of the code are 1 (pdf) and 2 (pdf).

*GW* method takes into account of the RPA correlation in the first-principles calculation.

fullpotentail *GW*sc result of La0.7Sr0.3MnO3,
which is known as a candidate of capacitance of RRAM and MRAM.

->
explanation (pdf) (a work with Dr. Kotani.)

LSDA dispersion of La0.7Sr0.3MnO3

fullpotential self-consistent *GW*sc dispersion of La0.7Sr0.3MnO3

*GW* tetrahedron DOS (pdf) in Japanese
- tetrahedron DOS with imaginary part of self-energy.
The result is also written in the pdf above. (also see the Tools part.)

diffusion Monte-Calro, curve fit with the concept of Baysian statistics.

DNA can be a semiconductor like conducting polymers.

The hydrated divalent cation has the unoccupied state,
while the anhydrous one has the occupied state.
red: occupied state, blue: unoccupied state.

Dr. T. Ozaki's order(N) program to calculate electronic structure
with the local basis set.
You can make local basis sets and pseudopotentials easily.

-> link to Dr. Ozaki's web page

(C) Kino