Structure determination of [3Fe2S] complex with complicated pseudo-merohedric twinning

A route of solving crystal structures from complicated pseudo-merohedric twinning crystals was described. The structure of a [3Fe2S] complex was solved and refined in the space group of P 42/ n to R 1 factor of 0.1789. Consequently, by deleting one of the two disordered groups in the structure, a space group of Aea 2 for the absolute structure was found. The new absolute structure with four twinning components was refined to R 1 about 0.1171. At the final stage, the disorder was again added to the structure. The structure in space group Aea 2 with both twinning and disorder was refined to R 1 of 0.0722, which implies the special structure feature.