CsLiMgP2O7: A congruently melting pyrophosphate with a [LiMgP4O18] 6-membered ring fundamental building block

A new pyrophosphate crystal, CsLiMgP 2 O 7 , was successfully synthesized using the high-temperature solution method. It crystallizes in the orthorhombic system with space group Pnma (No. 62). CsLiMgP 2 O 7 features a [LiMgP 4 O 18 ] 6-membered ring fundamental building block composed of four PO 4 and two Li/MgO 4 tetrahedrons, which connected with each other to form an interesting 6-membered ring chain. The DSC analysis proves that CsLiMgP 2 O 7 melts congruently. The spectral analyses were performed on the title compound, and the relationship between the electronic structures and optical properties has also been investigated by theoretical calculations.