Crystal structure and electronic structure of the quaternary oxysulfide Sr3Ge3OS8

As part of an ongoing investigation into group 2 germanium oxychalcogenides, a previously unreported compound, Sr 3 Ge 3 OS 8 , was identified. This compound crystallizes in the centrosymmetric Pnma space group. Sr 3 Ge 3 OS 8 has lattice parameters a = 15.6628(6) Å, b = 13.9919(5) Å, c = 6.6687(3) Å, and Z = 4. Sr 3 Ge 3 OS 8 does not adopt any known structure type, thus a new structure type has been discovered. DFT calculations predict that the material is a semiconductor with a band gap in the visible range, calculated at 2.55 eV.