Since it will be closed in September 2025, I tried the new version but cannot obtain the interface’s structure or surface with CIF. Many equations of state (EOS) and elastic stiffness (elastic constants) in the legacy version are missing. For example, Al is missing elastic stiffness (elastic constants). The names in the CIF structure download are the element names and no longer MP #, making them difficult to manage. Both are possible in the legacy version. Is it possible to completely switch to the new version in September 2025 and make up for these missing things? In my opinion, the legacy version should remain as it is.
Can you clarify which EOSes are missing? These data have not been updated in the legacy to nextgen transition, so all EOS data should be consistent between sites.
For the elastic tensors: we are more rigorously validating elastic tensors now than on the legacy site, and the nextgen site includes newer elastic tensor data. For the case you mentioned, fcc Al / mp-134, the newer elastic tensor data has unphysically negative eigenvalues and shear moduli, and is therefore not shown on the site.
You can still programmatically access these “deprecated” elastic data via our API client:
from mp_api.client import MPRester
with MPRester("your_api_key") as mpr:
elastic_doc = mpr.materials.elasticity.search(material_ids=['mp-134'])[0]
print(elastic_doc.elastic_tensor.ieee_format)
>>> ((70.0, 80.0, 80.0, -0.0, 0.0, 0.0), (80.0, 70.0, 80.0, -0.0, 0.0, 0.0), (80.0, 80.0, 70.0, -0.0, -0.0, 0.0), (-0.0, -0.0, -0.0, -28.0, -0.0, -0.0), (0.0, 0.0, -0.0, -0.0, -28.0, 0.0), (0.0, 0.0, 0.0, -0.0, 0.0, -28.0))
You also mention that “you cannot obtain the interface’s structure or surface with CIF”. Could you elaborate what you mean and where you’d expect to find this download functionality on the new website?
As for the file names of the CIF downloads, it looks like you’re referring to the CIF file being downloaded as Fe3Co_mp-601820_computed.cif on legacy vs Fe3Co.cif on the new website? If so, that should be something we can change easily.