ISOTHERMAL COMPRESSIBILITY AND PRESSURE-DEPENDENCE OF THE CRYSTAL-STRUCTURES OF THE SUPERCONDUCTING CHARGE-TRANSFER SALT KAPPA-(BEDT-TTF)(2)CU(NCS)(2) [BEDT-TTF=BIS(ETHYLENEDITHIO) TETRATHIAFULVALENE]

From the pressure dependence of the lattice parameters measured by sin gle-crystal X-ray diffraction at room temperature, the amplitudes and directions of the principal components of the isothermal compressibili ty tensor of kappa-(BEDT-TTF)(2)Cu(NCS)(2), bis(ethylenedithio)tetrath iafulvalene copper dithiocyanate have been determined from 1 x 10(5) P a to 12.9 x 10(5) kPa. The crystal structure has been determined at 1 x 10(5) Pa and 7.5 x 10(5) kPa. From the latter, the pressure dependen ce of the intermolecular electron-transfer integrals and the band stru cture have been calculated and compared with those at 1 x 10(5) Pa and 15 K.