Hi Team, I downloaded bulk modulus data from mp-api using the command below:
with MPRester(API_KEY) as mpr:
docs = mpr.materials.summary.search(k_vrh=(20000, 4000000), fields=["bulk_modulus", "material_id", "formula_pretty"])
# Process the retrieved data (e.g., print or save to a file)
for doc in docs:
print(f"Material ID: {doc.material_id}, Formula: {doc.formula_pretty}, Bulk Modulus: {doc.bulk_modulus} GPa")
The first line that was printed was mp-3597 (BaRuO3) with 1442373.521 GPa K_VRH.
Material ID: mp-3597, Formula: BaRuO3, Bulk Modulus: {'voigt': 2884558.595, 'reuss': 188.447, 'vrh': 1442373.521} GPa
When I tried to lookup this mp-id’ bulk modulus on the webapp(https://next-gen.materialsproject.org/materials/mp-3597?material_ids=mp-3597), it seems to be missing. In my discussion with @mattmcdermott, he identified that the 'elasticity': False for some entried despite having bulk modulus:
{..., 'has_props': {'materials': True,
'thermo': True,
'xas': True,
'grain_boundaries': False,
'chemenv': True,
'electronic_structure': True,
'absorption': False,
'bandstructure': True,
'dos': True,
'magnetism': True,
'elasticity': False,
'dielectric': False,
'piezoelectric': False,
'surface_properties': False,
'oxi_states': True,
'provenance': True,
'charge_density': True,
'eos': False,
'phonon': False,
'insertion_electrodes': False,
'substrates': True},
'theoretical': False,
'database_Ids': None,
'fields_not_requested': ['database_Ids']}}
After delving into the problem some more, we realize there are other mp-ids affected by this, as the webapp had 10,997 entries with bulk modulus whereas api reponse returned 12,921 as of Jul 9, 2025. Let us know if some values were retired or deprecated which are not shown on webapp or it is a data issue?
cc: @Aaron_Kaplan