Twinned dichlorobis(2,6-dichloropyrazine-N-4)zinc(II)

For crystals of the title compound, [ZnCl2(C4H2Cl2N2)(2)], metric considera tions suggest a monoclinic unit cell. However, the symmetry of the diffract ion pattern shows the crystals to be triclinic, with very similar lattice c onstants a and b, and alpha and beta. All crystals examined were twinned. T he discrepancy between the reliability indices for merging in the monoclini c lattice metric symmetry and the triclinic crystal symmetry constitutes an indicator for the volume ratio between the components. The asymmetric unit contains three independent molecules. At the molecular level, the compound shows a distorted tetrahedral coordination around one Zn atom.