Heavy alkali halide sulphide and selenide glasses are promising hosts for active and passive optical devices. Lithium and sodium chalcohalide glasses exhibit high ionic conductivity and can be used for battery applications. The atomic structure of these glasses is extensively studied using spectroscopic techniques but the diffraction studies are rare. Recently, we have used a combination of neutron and high-energy x-ray diffraction to unveil the short and intermediate range order in NaCl-Ga2S3-GeS2 glasses. Surprisingly, the sodium tetrahedral environment in these glasses appears to be mixed with Na-Cl and Na-S neighbours. This structural information has never mentioned in available literature and allows a new insight into atomic structure of these practically important chalcohalide glasses. Consequently, we aim to investigate whether the mixed alkali environment exist for K and Rb