[
  {
    "molid": "mol9216",
    "smiles": "O=C(O)CCC(=O)NO",
    "microspecies": [
      {
        "id": "0_1",
        "charge": 0,
        "smiles": "O=C(O)CCC(=O)NO",
        "std_free_energy": -3.8304667472839355,
        "relative_population": 1.0
      },
      {
        "id": "-1_2",
        "charge": -1,
        "smiles": "O=C([O-])CCC(=O)NO",
        "std_free_energy": -9.326946258544922,
        "relative_population": 0.9998868696157608
      },
      {
        "id": "-2_1",
        "charge": -2,
        "smiles": "O=C([O-])CCC(=O)N[O-]",
        "std_free_energy": -2.0477685928344727,
        "relative_population": 1.0
      }
    ],
    "macro_pka_values": [
      {
        "pka_value": 4.5,
        "charge_state_pre": 0,
        "charge_state_post": -1,
        "data_source": "IUPAC digitized pKa"
      },
      {
        "pka_value": 9.6,
        "charge_state_pre": -1,
        "charge_state_post": -2,
        "data_source": "IUPAC digitized pKa"
      }
    ]
  }
]