Figure 1 A (100) view of the structure with the independent atoms drawn in full 50% displacemenet ellipsoids and full bonds. The symmetry related part, in open ellipsoids and hollow bonds. Hydrogen interactions drawn in broken lines. Symmetry codes: (i) x, -y + , z + ; (ii) -x + 1, y - , -z + ; (iii) -x, y - , -z + ; (iv) -x, y + , -z + . (v) x - 1, y, z; (vi) -x + 1, -y, -z; (vii) -x, -y, -z.