Figure 1 View of a fragment of the title compound with displacement ellipsoids for non-H atoms are drawn at the 50% probability level. symmetry code: i = x,-1 + y,z; ii = x,1 + y,z; iii = 1 - x,-1 + y,1/2 - z; iv = 1 - x,y,1/2 - z; vi = [{3\over 2}] - x,1/2 - y,-z; vii = [{1\over 2}] + x,-[{1\over 2}] - y,-[{1\over 2}] + z; xii = [{3\over 2}] - x,1/2 - y,1/2 - z  [article HTML]