; a =11.030(1); b = 12.533(1); c = 16.241 (1) Angstrom; alpha = 68.585(7); beta = 75.197(5); gamma = 83.991(7)degrees; V = 2020.6(3) Angstrom(3); Z = 2; D-calc = 1.324 g cm(-3), mu(Mo-K-alpha) = 0.441 mm(-1); R-1 = 0.0325; wR(2) = 0.0875 for 415 parameters and 6823 independent reflections [R-int = 0.0177] with I = 2 sigma(I). The molecule shows a four-legged piano-stool geometry with two terminal OH ligands in a relative trans configuration. The complex EPR properties indicate that an equilibrium mixture of various species is present in solution. (C) 2000 Elsevier Science S.A. All rights reserved.