Query NOMAD for perovskite compositions

This notebook demonstrates how query NOMAD for perovskite compositions. The notebook also shows how to validate the ions against the JSON Schema

Basic imports¶

In [1]:

import json

import requests

base_url = 'http://nomad-lab.eu/prod/v1/api/v1'

import json import requests base_url = 'http://nomad-lab.eu/prod/v1/api/v1'

Query for a lead perovskite with band gap less than 1.65 eV¶

In [2]:

response = requests.post(
    f'{base_url}/entries/archive/query',
    json={
        'owner': 'visible',
        'query': {
            'results.eln.sections:any': ['PerovskiteComposition'],
            'results.material.elements:all': ['Pb'],
            'results.properties.electronic.band_gap.value': {
                'lte': 2.6435914460999996e-19
            },
        },
        'pagination': {'page_size': 1},
    },
)
response_json = response.json()
composition_data = response_json['data'][0]['archive']['data']
print(json.dumps(composition_data, indent=2))

response = requests.post( f'{base_url}/entries/archive/query', json={ 'owner': 'visible', 'query': { 'results.eln.sections:any': ['PerovskiteComposition'], 'results.material.elements:all': ['Pb'], 'results.properties.electronic.band_gap.value': { 'lte': 2.6435914460999996e-19 }, }, 'pagination': {'page_size': 1}, }, ) response_json = response.json() composition_data = response_json['data'][0]['archive']['data'] print(json.dumps(composition_data, indent=2))

{
  "m_def": "perovskite_solar_cell_database.composition.PerovskiteComposition",
  "short_form": "MAPbI",
  "long_form": "MAPbI3",
  "composition_estimate": "Estimated from precursor solutions",
  "sample_type": "Polycrystalline film",
  "dimensionality": "3D",
  "band_gap": 1.63,
  "name": "MAPI",
  "datetime": "2025-03-31T09:09:48.394259+00:00",
  "ions_a_site": [
    {
      "m_def": "perovskite_solar_cell_database.composition.PerovskiteAIonComponent",
      "system": "../uploads/ztDkTFJETdiMgrnRQSgsEA/archive/ZHsLIxapQ6idJZjA25Zohc8FRZzr#/data",
      "common_name": "Methylammonium",
      "molecular_formula": "CH6N+",
      "smiles": "C[NH3+]",
      "iupac_name": "methylazanium",
      "cas_number": "17000-00-9",
      "abbreviation": "MA",
      "source_compound_molecular_formula": "CH5N",
      "source_compound_smiles": "CN",
      "source_compound_iupac_name": "methanamine",
      "source_compound_cas_number": "74-89-5",
      "coefficient": "1"
    }
  ],
  "ions_b_site": [
    {
      "m_def": "perovskite_solar_cell_database.composition.PerovskiteBIonComponent",
      "system": "../uploads/ztDkTFJETdiMgrnRQSgsEA/archive/CIsbAqf80HCIft4qH3pjCdKuCOUr#/data",
      "common_name": "Lead",
      "molecular_formula": "Pb2+",
      "smiles": "[Pb+2]",
      "iupac_name": "lead(2+)",
      "cas_number": "14280-50-3",
      "abbreviation": "Pb",
      "source_compound_molecular_formula": "Pb",
      "source_compound_smiles": "[Pb]",
      "source_compound_iupac_name": "Lead",
      "source_compound_cas_number": "7439-92-1",
      "coefficient": "1"
    }
  ],
  "ions_x_site": [
    {
      "m_def": "perovskite_solar_cell_database.composition.PerovskiteXIonComponent",
      "system": "../uploads/ztDkTFJETdiMgrnRQSgsEA/archive/EtZIjsyxaPFuo4Hod84m-EcffFNe#/data",
      "common_name": "Iodide",
      "molecular_formula": "I-",
      "smiles": "[I-]",
      "iupac_name": "Iodide",
      "cas_number": "20461-54-5",
      "abbreviation": "I",
      "source_compound_molecular_formula": "I2",
      "source_compound_smiles": "II",
      "source_compound_iupac_name": "molecular iodine",
      "source_compound_cas_number": "7553-56-2",
      "coefficient": "3"
    }
  ],
  "elemental_composition": [
    {
      "element": "Pb",
      "atomic_fraction": 0.08333333333333333,
      "mass_fraction": 0.3342051647117734
    },
    {
      "element": "C",
      "atomic_fraction": 0.08333333333333333,
      "mass_fraction": 0.019372770134187728
    },
    {
      "element": "N",
      "atomic_fraction": 0.08333333333333333,
      "mass_fraction": 0.0225922368753301
    },
    {
      "element": "H",
      "atomic_fraction": 0.5,
      "mass_fraction": 0.009754597115431996
    },
    {
      "element": "I",
      "atomic_fraction": 0.25,
      "mass_fraction": 0.6140752311632768
    }
  ],
  "components": [
    {
      "m_def": "perovskite_solar_cell_database.composition.PerovskiteAIonComponent",
      "system": "../uploads/ztDkTFJETdiMgrnRQSgsEA/archive/ZHsLIxapQ6idJZjA25Zohc8FRZzr#/data",
      "common_name": "Methylammonium",
      "molecular_formula": "CH6N+",
      "smiles": "C[NH3+]",
      "iupac_name": "methylazanium",
      "cas_number": "17000-00-9",
      "abbreviation": "MA",
      "source_compound_molecular_formula": "CH5N",
      "source_compound_smiles": "CN",
      "source_compound_iupac_name": "methanamine",
      "source_compound_cas_number": "74-89-5",
      "coefficient": "1"
    },
    {
      "m_def": "perovskite_solar_cell_database.composition.PerovskiteBIonComponent",
      "system": "../uploads/ztDkTFJETdiMgrnRQSgsEA/archive/CIsbAqf80HCIft4qH3pjCdKuCOUr#/data",
      "common_name": "Lead",
      "molecular_formula": "Pb2+",
      "smiles": "[Pb+2]",
      "iupac_name": "lead(2+)",
      "cas_number": "14280-50-3",
      "abbreviation": "Pb",
      "source_compound_molecular_formula": "Pb",
      "source_compound_smiles": "[Pb]",
      "source_compound_iupac_name": "Lead",
      "source_compound_cas_number": "7439-92-1",
      "coefficient": "1"
    },
    {
      "m_def": "perovskite_solar_cell_database.composition.PerovskiteXIonComponent",
      "system": "../uploads/ztDkTFJETdiMgrnRQSgsEA/archive/EtZIjsyxaPFuo4Hod84m-EcffFNe#/data",
      "common_name": "Iodide",
      "molecular_formula": "I-",
      "smiles": "[I-]",
      "iupac_name": "Iodide",
      "cas_number": "20461-54-5",
      "abbreviation": "I",
      "source_compound_molecular_formula": "I2",
      "source_compound_smiles": "II",
      "source_compound_iupac_name": "molecular iodine",
      "source_compound_cas_number": "7553-56-2",
      "coefficient": "3"
    }
  ]
}

Validate response against JSON Schema¶

In [3]:

from jsonschema import ValidationError, validate

schema_id = (
    'https://raw.githubusercontent.com/Jesperkemist/'
    'Perovskite_composition/v1.0.0/perovskite_composition_schema.json'
)

# Load the JSON schema from the URL
schema_response = requests.get(schema_id)
schema = schema_response.json()

# Validate ion_data against the schema
try:
    validate(instance=composition_data, schema=schema)
    print(f'composition_data is valid against the {schema_id} schema.')
except ValidationError as e:
    print('Validation error:', e.message)

from jsonschema import ValidationError, validate schema_id = ( 'https://raw.githubusercontent.com/Jesperkemist/' 'Perovskite_composition/v1.0.0/perovskite_composition_schema.json' ) # Load the JSON schema from the URL schema_response = requests.get(schema_id) schema = schema_response.json() # Validate ion_data against the schema try: validate(instance=composition_data, schema=schema) print(f'composition_data is valid against the {schema_id} schema.') except ValidationError as e: print('Validation error:', e.message)

composition_data is valid against the https://raw.githubusercontent.com/Jesperkemist/Perovskite_composition/v1.0.0/perovskite_composition_schema.json schema.