Gallium(II) sulfide, GaS, is a chemical compound of gallium and sulfur. The normal form of gallium(II) sulfide as made from the elements has a hexagonal layer structure containing Ga24+ units which have a Ga-Ga distance of 248pm. This layer structure is similar to GaTe, GaSe and InSe.
Molar mass：101.788 g mol−1
Density：3.86 g cm−3
Melting point：965 °C (1,769 °F; 1,238 K)
Magnetic susceptibility (χ)：−-23.0·10−6 cm3/mol
Crystal structure：hexagonal, hP8