Figure 1 View of the title compound with the atom numbering scheme. Displacement ellipsoids for non-H atoms are drawn at the 50% probability level. All H atoms have been omitted for clarity. [Symmetry code: (i) x - 1, y, z; (ii) -x + 1, -y + 1, -z + 1; (iii) -x + 1, -y + 1, -z + 2.]  [article HTML]