[
  {
    "molid": "mol28328",
    "smiles": "O=S(=O)(O)NS(=O)(=O)O",
    "microspecies": [
      {
        "id": "-3_1",
        "charge": -3,
        "smiles": "O=S(=O)([O-])[N-]S(=O)(=O)[O-]",
        "std_free_energy": -9.918623924255371,
        "relative_population": 1.0
      },
      {
        "id": "-2_1",
        "charge": -2,
        "smiles": "O=S(=O)([O-])NS(=O)(=O)[O-]",
        "std_free_energy": -14.392643928527832,
        "relative_population": 0.6051461420522426
      },
      {
        "id": "-2_2",
        "charge": -2,
        "smiles": "O=S(=O)([O-])[N-]S(=O)(=O)O",
        "std_free_energy": -13.965689659118652,
        "relative_population": 0.3948538579477574
      }
    ],
    "macro_pka_values": [
      {
        "pka_value": 8.5,
        "charge_state_pre": -2,
        "charge_state_post": -3,
        "data_source": "OCHEM"
      }
    ]
  }
]