Figure 1 View of the structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are represented as spheres of arbitrary radii [symmetry codes: (i) x + 1, y, -z + [{1\over 2}]; (ii) x, y, -z + [{1\over 2}]; (iii) x + 1, y, z; (v) x + 1, -y + 1, -z; (vii) x + 1, -y + 1, z + [{1\over 2}]; (viii) x + 1, -y + 1, z - [{1\over 2}]; (ix) x, -y + 1, z - [{1\over 2}]; (x) x, -y + 1, -z; (xvii) x, -y + 1, z + [{1\over 2}]; (xviii) x, -y + 1, -z + 1; (xix) x + 1, -y + 1, -z + 1].  [article HTML]