Crystal structure of a superionic conductor, Li7P3S11

Abstract A synchrotron X-ray powder diffraction pattern was measured for a lithium superionic conductor, Li 7 P 3 S 11 , which has a high conductivity of 3.2 × 10 − 3  S cm − 1 at room temperature and a low activation energy of 12 kJ mol − 1 [Mizuno et al., Solid State Ionics, vol. 177 (2006) 2721]. The crystal structure was solved by a direct space global optimization technique and refined by the Rietveld method. The compound crystallizes in a triclinic cell, space group P -1, a =  12.5009(3) A, b =  6.03160(17) A, c =  12.5303(3) A, α =  102.845(3)°,  β =  113.2024(18)°, γ =  74.467(3)°. PS 4 tetrahedra and P 2 S 7 ditetrahedra are contained in the structure and Li ions are situated between them.