Abstract
Up to now, very few results concerning the crystal structure of molecular compounds have been obtained by X-ray diffraction under pressure; such an experiment has been set up in our laboratory and several molecular superconductors have been studied for the last five years. We report, besides some technical information about the method, the compressibility tensor calculated from the pressure dependence(<12kbar) of the cell parameters and the structural and electronic properties of the organic superconductor (TMTSF)2 CIO4 derived from the complete X-ray crystal structure determination, performed at 4,6 and 9. 5kbar.