A low-temperature neutron diffraction study of Mn12-acetate

In the low-temperature region, where the dodecanuclear mixed-valence manganese carboxylate hexadecaacetatotetra-aquadodecaoxododecamanganese bis(acetic acid) tetrahydrate, [Mn12O12(C2D3O2)(16)(H2O)(4)]. 2C(2)HD(3)O(2). 4H(2), displays unusual magnetic properties, its structure is similar to that previously determined at room temperature [Lis (1980). Acta Cryst. B36, 2042-2046], differing only by a small change in the configuration of one of the coordinated acetate groups, related to the formation of additional hydrogen bonds, and by the orientation of the methyl groups. Since most of the magnetization density of this system resides on the Mn atoms, the consequences of these rearrangements for the magnetic properties of the compound are small.