Table 2 The effect of using the non-standard option FixedH on the InChI and Universal SMILES

SMILES

Standard InChI

InChI Auxiliary info

“Universal” SMILES

C(=O)([O-])C(=O)O

InChI=1/C2H2O4/c3-1(4)2(5)6/h(H,3,4)(H,5,6)/p-1

AuxInfo =1/1/N:1,4,2,3,5,6/E:(1,2)(3,4,5,6)/gE:(1,2)/rA:6COO-COO/rB:d1;s1;s1;d4;s4;/rC:;;;;;;

C(=O)(C(=O)O)[O-]

C(=O)(O)C(=O)[O-]

InChI=1/C2H2O4/c3-1(4)2(5)6/h(H,3,4)(H,5,6)/p-1

AuxInfo=1/1/N:1,4,2,3,5,6/E:(1,2)(3,4,5,6)/gE:(1,2)/rA:6COOCOO-/rB:d1;s1;s1;d4;s4;/rC:;;;;;;

C(=O)(C(=O)[O-])O

SMILES

Non-standard InChI*

InChI Auxiliary info

Universal SMILES

C(=O)([O-])C(=O)O

InChI=1/C2H2O4/c3-1(4)2(5)6/h(H,3,4)(H,5,6)/p-1/fC2HO4/h3H/q-1

AuxInfo=1/1/N:1,4,2,3,5,6/E:(1,2)(3,4,5,6)/gE:(1,2)/F:4,1,6,5,2,3/E:(5,6)/rA:6COO-COO/rB:d1;s1;s1;d4;s4;/rC:;;;;;;

C(=O)(C(=O)[O-])O

C(=O)(O)C(=O)[O-]

InChI=1/C2H2O4/c3-1(4)2(5)6/h(H,3,4)(H,5,6)/p-1/fC2HO4/h3H/q-1

AuxInfo=1/1/N:1,4,2,3,5,6/E:(1,2)(3,4,5,6)/gE:(1,2)/F:1,4,3,2,5,6/E:(5,6)/rA:6COOCOO-/rB:d1;s1;s1;d4;s4;/rC:;;;;;;

C(=O)(C(=O)[O-])O