A new quaternary rare earth borate, CsLi2Gd4(BO3)5

Single crystals of caesium dilithium tetra­gadolinium penta­borate, CsLi2Gd4(BO3)5, were obtained by heating lithium and gadolinium in a caesium borate flux. The structure features chains of edge- and corner-sharing GdOn polyhedra. These chains are inter­locked to form [Gd8O16(BO3)2]14− layers, which are connected by borate groups in the third dimension. The Li and Cs atoms occupy O5 pyramids and large cages in the framework, respectively.