[
  {
    "molid": "mol21884",
    "smiles": "O=S(=O)(O)O",
    "microspecies": [
      {
        "id": "0_1",
        "charge": 0,
        "smiles": "O=S(=O)(O)O",
        "std_free_energy": 15.83609390258789,
        "relative_population": 1.0
      },
      {
        "id": "-1_1",
        "charge": -1,
        "smiles": "O=S(=O)([O-])O",
        "std_free_energy": -11.327569961547852,
        "relative_population": 1.0
      }
    ],
    "macro_pka_values": [
      {
        "pka_value": 1.9,
        "charge_state_pre": 0,
        "charge_state_post": -1,
        "data_source": "OCHEM"
      },
      {
        "pka_value": 2.0,
        "charge_state_pre": 0,
        "charge_state_post": -1,
        "data_source": "QSARToolbox"
      }
    ]
  }
]