Crystal structure of a superionic conductor, Li7P3S11

A synchrotron X-ray powder diffraction pattern was measured for a lithium superionic conductor, Li7P3S11, 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) Å, b = 6.03160(17) Å, c = 12.5303(3) Å, α = 102.845(3)°,  β = 113.2024(18)°, γ = 74.467(3)°. PS4 tetrahedra and P2S7 ditetrahedra are contained in the structure and Li ions are situated between them.