The crystal structure of the monohydrate R2Mo6O21·H2O (R=Pr, Nd, Sm, and Eu): a layer structure containing disordered [Mo2O7]2− groups

The crystal structure of R2O3:MoO3=1:6 (R: rare earth) phase consists of disordering [Mo2O7]2− groups, and [RO8] and [R(H2O)O8] polyhedra.