Figure 1. Molecular arrangement and electronic structure of κ-Cl without electron correlation.

(a) Molecular arrangement of the BEDT-TTF layer and the effective anisotropic triangular lattice. t is the nearest-neighbour hopping (solid line) and t' is the next-nearest-neighbour hopping (dashed line) between the BEDT-TTF dimers. Two differently oriented dimers are indicated by red and blue shades. (b) Schematic representation of Fermi surface without electron interaction. The first BZ of κ-Cl is indicated by a solid square. (c) Tight-binding band structure and DOS for t'/t=−0.8 with t=55 meV. Here, Γ=(0,0), Z=(0,π/c), M=(π/a,π/c) and X=(π/a,0). The Fermi energy is denoted by dashed lines. DOS, density of states.