The class of chemicals called boride oxides contain both boride and oxide anions. They are mixed anion compounds.
Examples include Li6B18(Li2O)x. This contains Li6B18 containing hollow channels where variable amounts of Li2O can be contained or conducted. It crystallises in space group P6/mmm a=8.217 c=4.159.[1]
- ^ Delacroix, Simon; Le Godec, Yann; Coelho-Diogo, Cristina; Gervais, Christel; Génois, Isabelle; Le Griel, Patrick; Portehault, David (19 October 2020). "Synthesis in Molten Salts and Characterization of Li 6 B 18 (Li 2 O) x Nanoparticles". Inorganic Chemistry. 59 (20): 14983–14988. doi:10.1021/acs.inorgchem.0c01694.