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Cooperation of antiferromagnetism and superconductivity is achieved and reported by Kobayashi and his co-workers. For the BETS related crystals, κ-(BETS) 2 FeCl 4 (BETS=bis(ethylenedithio)tetraselenafulvalene), effective exchange integrals ( J ab ) between two BETS + molecules (Step I) and between BETS + and FeCl 4 - molecules (Step II) are very important to reveal superconductivity and successfully evaluated in our treatments. organic superconductor effective exchange integral BETS ab initio MO DFT [ABSTRACT FROM AUTHOR]

Magnetic interactions between divalent chromium (Cr(II)) ions in tetra Cr(II) complex were estimated by using a magnetic effective density functional (MEDF) method. Those results were discussed in comparison with a di-Cr(II) complex to elucidate the types of magnetic interactions. Charge and spin densities and natural orbitals by MEDF were also examined in terms of the ligand effects. aligned tetrametal systems magnetic interaction effective exchange integrals Magnetic Effective Density Functional MEDF [ABSTRACT FROM AUTHOR]

The spin alignment rule for the magnetic couplings of d-π-d conjugated systems via pyrimidine has been proposed on the basis of the superexchange (SE) interaction and spin polarization (SP) effects in order to predict the sign of J ab values between transition metal ions. This rule shows that the subtle balance of σ- and π- type SE interaction and SP effects determines the magnetic interaction of these systems. M(II) 2 -pyrimidine effective exchange interaction ( J ab ) superexchange (SE) interaction spin polarization (SP) effect [ABSTRACT FROM AUTHOR]

Phase diagrams of theoretical models for CuO 2 plane and CuO chains are presented by using a two-band model. Field-induced superconductivity Two-band model High-Tc superconductivity [ABSTRACT FROM AUTHOR]

Model clusters (NH 3 ) 4 +2 and (NM 3 -H 2 NO·) 4 +2 are introduced as simple models for a pure organic conductor. Then theoretical calculations of the total energies of ab initio solution, in which the spin or charge density are arranged alternately, and intermolecular magnetic interactions are carried out by ab initio MO-DFT method. The result shows that these model clusters are efficient for ab initio investigation of the electronic properties of organomagnetic conductors. ab initio MO calculation pure organomagnetic conductors effective exchange integrals cluster model [ABSTRACT FROM AUTHOR]

SDW and CDW states of [-O-M-O-M-O-M-O-M-](M=Cu, Ag)4 site periodic model were investigated. Our theoretical attempt is to elucidate the difference among group 11 metals; Cu, Ag, from the view point of stability on SDW/CDW states, and leads to prospect of their physical properties. SDW CDW charge fluctuation periodic model Cu and Ag oxides [ABSTRACT FROM AUTHOR]

The detailed theoretical studies for TCNQ/TCNQ -· salts, which possess ferromagnetic hysteresis at relative high temperature, were carried out. The calculations based on ab initio molecular orbital (MO) and density functional (DFT) theories were carried out to evaluate the intermolecular effective exchange integrals and transfer integrals. In addition, we employed the "hybrid DFT method" based on instability of chemical bonds and successfully studied their spin densities. From the results it was found the remarkable singlet dimer structure is dominant. In addition, quasi-one-dimensional structure was found because of nonzero charge transfer. [ABSTRACT FROM AUTHOR]

The effective exchange integrals for the naked Cr(II) tetramer are calculated by using post-Hartree-Fock and the improved hybrid density functional method. The calculated values are examined in comparison with naked Cr(II) dimer. The naked Cr(II) tetramer that is arranged similar to [Cr(II) 4 (DpyF) 4 Cl 2 ]Cl 2 also examined in terms of magnetic interactions. [ABSTRACT FROM AUTHOR]