Basic Barium Phosphates

A compound, Ba₃(PO₄)₂.Ba(OH)₂, corresponding to calcium tetraphosphate, has been isolated, and also the compounds 3BaO.2P₂O₅ and 5BaO.3P₂O₅. It is possible that these are to be regarded as salts of polyphosphoric acids rather than as basic salts.