HG
  -OEChem-04192423343D

  1  0  0     0  0  0  0  0  0999 V2000
    0.0000    0.0000    0.0000 Hg  0  2  0  0  0  0  0  0  0  0  0  0
M  CHG  1   1   2
M  END
> <OPENEYE_ISO_SMILES>
[Hg+2]

> <OPENEYE_INCHI>
InChI=1S/Hg/q+2

> <OPENEYE_INCHIKEY>
BQPIGGFYSBELGY-UHFFFAOYSA-N

> <FORMULA>
Hg+2

$$$$