STRUCTURE OF SRCOP2O7

Strontium cobalt diphosphate, M(r) = 320.50, monoclinic, P2(1)/n, a = 5.3165 (4), b = 8.2574 (5), c = 12.6755 (7) angstrom, beta = 90.133 (5)-degrees, V = 556.5 (1) angstrom 3, Z = 4, D(x) = 3.827 g cm-3, Mo K-alpha, lambda = 0.71073 angstrom, mu = 128.55 cm-1, F(000) = 604, T = 293 K, R = 0.041, wR = 0.048 for 1159 independent reflections with I greater-than-or-equal-to 3-sigma(I). The coordination about the Co atoms is 4 + 1 square pyramidal. The [CoO5] pyramids and the [P2O7] diphosphate units share their corners and realize a mixed framework with Sr ions located inside pentagonal tunnels running along [100].