Synthesis, structure, optical property, and electronic structure of Ba7AgGa5Se15

- A new quaternary chalcogenide Ba7AgGa5Se15 was synthesized.
- It adopts a new structure type in the space group P31c of the trigonal system.
- The structure contains a three-dimensional framework built from GaSe4 and AgSe4 tetrahedra.
- Ba7AgGa5Se15 is a direct semiconductor with the band gap of 2.60 (2) eV.
- The electronic structure was calculated to explain the optical properties.