P2O5 21.94, F 21.35, H2O (calculated by stoichiometry) 15.08, less F O 8.99, total 100.39 wt%. The empirical formula. based on 21 (17+% is (Ca3.98Mn0.02Fe0.01)(Sigma 4.0)Al-2.01(P1.99Si0.01)F-7.23(OH)(0.77)center dot 5H(2)O. The crystal structure, solved and refined using ...