The bulk β-Li 3 PS 4 and 75Li 2 S-25P 2 S 5 glass structures were prepared separately as initial structural data. These structures were used for classifying crystalline and glassy PS 4 3units and for constructing the interfacial model by joining bulk β-Li 3 PS 4 and 75Li 2 S-25P 2 S 5 glass.