Checkerboard-type charge-ordered state of a pressure-induced superconductor, beta-(meso-DMBEDT-TTF)2PF6.

To investigate the insulating state of the pressure-induced superconductor, beta-(meso-DMBEDT-TTF)2PF6, we have carried out X-ray analysis at 11.5 K. In an asymmetric unit, there exist two crystallographically independent donor molecules, caused by charge separation. In the column structure, the arrangement of the charge-rich (r) and -poor (p) donor molecules is as rrpprrpp, which affords "checkerboard"-type charge ordering.