[(2R,3S)-Butane-1,2,3,4-tetraol-κ(3) O (1),O (2),O (3)](ethanol-κO)tris-(nitrato-κ(2) O,O')samarium(III).

The title Sm(III)-erythritol complex, [Sm(NO3)3(C2H6O)(C4H10O4)], is isotypic with its Nd, Eu, Y, Gd, Tb and Ho analogues. The Sm(III) cation exhibits a coordination number of ten and is chelated by a tridentate erythritol ligand and three bidentate nitrate anions. It is additionally coordinated by an O atom of an ethanol mol-ecule, completing an irregular coordination sphere. The Sm-O bond lengths range from 2.416 (2) to 2.611 (2) Å. In the crystal, extensive O-H⋯O hydrogen bonding involving all hy-droxy groups and some of the nitrate O atoms links the mol-ecules into a three-dimensional network.