Caesium oxide (IUPAC name), or cesium oxide, describes inorganic compounds composed of caesium and oxygen. Several binary (containing only Cs and O) oxides of caesium are known.[1][2]
^Simon, A. (1997), "Group 1 and 2 Suboxides and Subnitrides — Metals with Atomic Size Holes and Tunnels", Coord. Chem. Rev., 163: 253–270, doi:10.1016/S0010-8545(97)00013-1.