[
  {
    "molid": "mol37108",
    "smiles": "O=C(O)C(=O)NO",
    "microspecies": [
      {
        "id": "-1_2",
        "charge": -1,
        "smiles": "O=C([O-])C(=O)NO",
        "std_free_energy": -11.386662483215332,
        "relative_population": 0.9987341013954212
      },
      {
        "id": "-2_2",
        "charge": -2,
        "smiles": "O=C([O-])C(=O)N[O-]",
        "std_free_energy": -2.9580349922180176,
        "relative_population": 0.5973228658629727
      },
      {
        "id": "-2_3",
        "charge": -2,
        "smiles": "O=C([O-])C(=O)[N-]O",
        "std_free_energy": -2.562608480453491,
        "relative_population": 0.40223289806495455
      }
    ],
    "macro_pka_values": [
      {
        "pka_value": 8.69999980926514,
        "charge_state_pre": -1,
        "charge_state_post": -2,
        "data_source": "QSARToolbox"
      }
    ]
  }
]