ANALYSIS OF THE DIFFRACTION PATTERN OF A TWINNED CRYSTAL OF (3,4-3',4'-BIS(ETHYLENEDIOXO)-2,2',5,5'-TETRATHIAFULVALENE)(2).AG(CN)(2)

A strategy is described for recognition of partially overlapped reflections of a twinned crystal. Potentially overlapping reflections are identified by comparison of the Miller indices after transformation to a single basis set for all twin components. Overlapping reflections are subsequently rejected or accepted for structure determination based on their calculated separation in the omega-scanning angle. The method is applied to a twinned crystal of 6,6'-bi(2,3-dihydro[1,3]-dithiolo[5,4-b] diox-6-yliden)ium dicyanoargentate, [C10H8O4S4](2)-[Ag(CN)(2)], M(r) = 800.76, triclinic, P ($) over bar 1, a = 4.0355 (1), b = 16.7566(2), c = 10.2335(1)Angstrom, alpha = 82.49(1), beta = 81.12(1), gamma = 91.10(2)degrees, V = 677.3(3)Angstrom(3), Z = 1, D-calc = 1.963 g cm(-3) Mo K alpha = 0.71073 Angstrom, mu = 13.805 cm(-1), F(000) = 401, room temperature, R(F) = 0.0642, for 1250 reflections. The structure consists of stacks of BEDO-TTF cations [BEDO-TTF = bis(ethylenedioxo)tetrathiafulvalene] a. Short S-S contacts of 3.433 and 3.500 Angstrom occur between the BEDO-TTF molecules within sheets perpendicular to the stacking direction.