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 P42/n to R1 factor of 0.1789. Consequently, by deleting one of the two disordered groups in the structure, a space group of Aea2 for the absolute structure was found. The new absolute structure with four twinning components was refined to R1 about 0.1171. At the final stage, the disorder was again added to the structure. The structure in space group Aea2 with both twinning and disorder was refined to R1 of 0.0722, which implies the special structure feature.