Structure of SbxGe40-xSe60 glasses around 2.67 average coordination number

► Validation of the concept of nano-scale segregation in chalcogenide glass, ChG. ► First clue to the chemical identity of nano-scale inhomogeneity in ChG. ► Powerful demonstration of XPS as tool for identifying structural moieties in glass. ► Basic structure of commercially important ternary ChG.