β‐Sm(OH)2Cl: a new lamellar variety

Crystals of dihydroxysamarium chloride were synthesized hydro­thermally at 473 K. The orthorhombic structure was determined by single‐crystal X‐ray diffraction analysis. β‐­Sm(OH)₂Cl exhibits a lamellar structure built up from the stacking of neutral slabs; all the atoms lie on crystallographic mirror planes. The structure is stabilized by strong hydrogen bonds between the OH groups and the Cl ions of adjacent layers.