[
  {
    "molid": "mol33799",
    "smiles": "O=C(O)CCC(=O)CCC(=O)O",
    "microspecies": [
      {
        "id": "0_1",
        "charge": 0,
        "smiles": "O=C(O)CCC(=O)CCC(=O)O",
        "std_free_energy": -2.360077381134033,
        "relative_population": 1.0
      },
      {
        "id": "-1_1",
        "charge": -1,
        "smiles": "O=C([O-])CCC(=O)CCC(=O)O",
        "std_free_energy": -7.9624857902526855,
        "relative_population": 0.9998602668329044
      }
    ],
    "macro_pka_values": [
      {
        "pka_value": 4.21999979019165,
        "charge_state_pre": 0,
        "charge_state_post": -1,
        "data_source": "QSARToolbox"
      }
    ]
  }
]