The crystal structure of connellite has been solved from the Patterson function and refined to an R factor of 0.07. The structure analysis shows the most probable space group to be P62c. The most probable chemical composition of the crystal studied is:
Cu36.8[(SO4).8, (NO3).2]2Cl6(OH)60[C1.33, (OH).33, (H2O).33]6.6H2O
The structure consists of an intricate three-dimensional framework which contains large channels parallel to the c axis. In overall aspect, however, the structure is geometrically simple. The framework is composed of edge and corner-sharing polyhedra with Cu2+ as the central ion and apices composed of (OH)−, Cl−, and H2O. The polyhedra are, with one exception, distorted octahedra. The channel contains the disordered SO4 ion. The disorder is the result of the tetrahedral SO4 filling a 6 site and an apparent one for one substitution of NO3 for SO4.