BAND-STRUCTURE AND PHYSICAL-PROPERTIES OF AN ORGANIC CONDUCTOR (BEDT-TTF)4CU(C2O4)2

The crystal and electronic band structures of a novel quasi-three-dimensional organic conductor (BEDT-TTF)4Cu(C2O4)2 (BEDT-TTF: bis(ethylenedithio)tetrathiafulvalene) are reported. The anomalies at about 260, 160 and 65 K, which have been detected from the temperature dependence of resistivity and ESR, are discussed by comparing with the specific heat measurement result. The anomalies at about 260 and 160 K can be considered to be a kind of metal-metal transition related to the lattice distortion. The anomaly at about 65 K is a metal-insulator transition which is dominated by the electronic transition.