Ca(H2PO4)2\mathrm{Ca}\left(\mathrm{H}_{2} \mathrm{PO}_{4}\right)_{2}Ca(H2PO4)2
(Ca(H2PO4)2)\left(\mathrm{Ca}\left(\mathrm{H}_{2} \mathrm{PO}_{4}\right)_{2}\right)(Ca(H2PO4)2)
(NH4)2HPO4\left(\mathrm{NH}_{4}\right)_{2} \mathrm{HPO}_{4}(NH4)2HPO4
NH4H2PO4\mathrm{NH}_{4} \mathrm{H}_{2} \mathrm{PO}_{4}NH4H2PO4