Hi Materials Project team,
I’m encountering a discrepancy between the results returned via the API and what is shown on the website when querying for the most stable structure of a pure element.
Using the MPRester API, I ran the following query to retrieve structures with:
- A single element (e.g.,
Ag) energy_above_hull = 0.0formation_energy = 0.0
Here is the code snippet I used:
from mp_api.client import MPRester
elements = ["Ag"]
with MPRester() as mpr:
structure_dict = {}
structure_id_dict = {}
for element in elements:
docs = mpr.materials.summary.search(
chemsys=element,
num_elements=1,
elements=[element],
energy_above_hull=(0.0000, 0.0000),
formation_energy=(0.0000, 0.0000),
fields=["energy_per_atom", "e_total", "material_id"]
)
for doc in docs:
print(doc.material_id, doc.energy_per_atom)
When I run this for Ag, the result includes mp-8566, but I noticed that on the website, the most stable silver structure appears to be mp-989737, which also has an energy above hull of 0 eV.
This leads me to a few questions:
-
Why does the API return
mp-8566as the stable structure for Ag, while the website seems to prefermp-989737? -
For selecting a representative or most stable structure for elemental Ag, which material ID should I use in my analysis?
Any guidance or clarification would be greatly appreciated!
Best regards,
Guangsheng
