Getting current MP elasticity data

[dwinston]

@HGeerlings asked about simple programmatic access to MP's elastic constants data. While there are no specific methods in pymatgen's MPRester yet, you can use it's query method in consultation with our API repository to fish out what to do. All elasticity data for a material is stored under the 'elasticity' root level key. For example,

from pymatgen import MPRester
# Assuming you've done `export MAPI_KEY="USER_API_KEY"` at the command line
# See materialsproject.org/dashboard to get your API key
m = MPRester()
data = m.query(criteria={"elasticity": {"$exists": True}},
                         properties=["formula", "elasticity.K_VRH"])
# print("{} results".format(len(data)))
# data[:5]

Will give you bulk moduli and reduced cell formulae (see materialsproject/mapidoc#7 for a list of "aliases") for all MP materials that have elasticity data (you'd get tens of thousands of None-valued results if you set criteria={} above).

Let me know if there are issues getting the above to run for you.

[HGeerlings]

Seems to work great.

For reference, thought I would share a helpful link I found on the MP github (courtesy of Donny) that lists other elastic properties.

Thanks!

[dwinston]

OK, looks like everyone's up and running with this!