Synthesis, Structure, and Optical Properties of K2.4Ga2.4M1.6Q8 (M: Si,Ge; Q: S, Se) Crystals and Glasses.

The title compounds are prepared by a reactive flux method involving K2Q2 (Q: S, Se) as the flux, Ga2Se3, Ge or Si, and Q in the molar ratio of 2.25:0.375:0.5:1.75 (evacuated silica tubes, 750 °C, 3 d; ≈80% yield).