Raman spectra of (MY)
x
(Ga2S3)0.2−0.2x
(GeS2)0.8−0.8x
pseudo-ternary glassy systems (M = Na, K, Rb; Y = Cl, Br, I) were investigated systematically as a function of MY nature and alkali content. Raman spectroscopy of the Ga3S3-GeS2 glassy matrix shows a complicated local structure: corner-sharing CS- and edge-sharing ES-GeS4/2 tetrahedra, Ga-S triclusters and ETH-Ga2S6/2 ethane-like units. The Ga2S6/2 population decreases with increasing x related to a substitution of some bridging sulfur atoms around central Ga by terminal Y species with a respective decrease of the network rigidity. The formation of mixed Ga-(S,Y) environment is affected by the M+ ion size and the MY concentration.