Single crystal x-ray study of pressure-induced metal-insulator transition in (DMeDCNQI)2Cu

The structures of the metallic and the insulating phases of (DMeDCNQI)2Cu were solved under pressures of up to 15.8 kbar at room temperature. An angle α representing the deformation of CuN4 tetrahedron around the Cu atom increases almost linearly with pressure at the rate of about 0.6 deg./ kbar. Furthermore, an X-ray diffuse scattering study revealed the presence of a 3 c CDW superlattice structure above 12 kbar in the high pressure insulating phase.