1 GB Methylphosphonic acid ester group 1.000 2 MMQ Mercaptomethyl phosphonate 0.833 3 PGL (aminomethyl)phosphonic acid 0.833 4 2PO Phosphonate 0.800 5 78T Oxidanylphosphinate 0.800 6 PHS Phosphonic acid 0.800 7 PO3 Phosphite ion 0.800 8 VXA Methylphosphonic acid ester group 0.800 9 2HE (2-hydroxyethyl)phosphonic acid 0.714 10 57H Prop-2-en-1-ylphosphonic acid 0.714 11 GG7 [(1r)-1-aminoethyl]phosphonic acid 0.714 12 P7I (2-aminoethyl)phosphonic acid 0.714 13 POA Phosphonoacetaldehyde 0.714 14 PPF Phosphonoformic acid 0.714