Syntheses, crystal structures, and characterizations of LiM(PO3)4 (M = Y, Dy)

Two tertiary rare earth polyphosphates, namely, LiM(PO3)4 (M = Y, Dy), have been synthesized by the solid-state reaction and structurally established by single-crystal X-ray diffraction (XRD). The two compounds crystallize in monoclinic space group C2/c and Z = 4. They are isostructural and the structures feature interconnected Y–Li straight chains and [PO4]3− wavy chains. Additionally, the calculations of band structure, density of states of LiY(PO3)4 were performed with the density functional theoretical (DFT) method and the optical properties of LiDy(PO3)4 were investigated in terms of emission spectra.