add poscar to data output for workflows

Author: esoteric-ephemera

mp_api/mcp/_schemas.py

@@ -5,6 +5,7 @@
 
 from emmet.core.summary import SummaryDoc
 from pydantic import BaseModel, Field, model_validator
+from pymatgen.core import Structure
 from typing_extensions import Self
 
 from mp_api.client.core.utils import validate_ids
@@ -266,6 +267,13 @@ class MaterialMetadata(BaseModel):
         ),
     )
 
+    poscar: str | None = Field(
+        None,
+        description=(
+            "The structure in VASP's POSCAR format: " "https://vasp.at/wiki/POSCAR"
+        ),
+    )
+
     cell_vectors: list[list[float]] | None = Field(
         None,
         description=(
@@ -368,6 +376,7 @@ def from_summary_data(cls, summary_data: dict[str, Any], **kwargs) -> Self:
                 site["properties"].get("magmom") for site in struct_dict["sites"]
             ]
             metadata.update(
+                poscar=Structure.from_dict(struct_dict).to(fmt="poscar"),
                 cell_vectors=struct_dict["lattice"]["matrix"],
                 atoms=[site["species"][0]["element"] for site in struct_dict["sites"]],
                 cartesian_coordinates=[site["xyz"] for site in struct_dict["sites"]],

mp_api/mcp/tools.py

@@ -234,7 +234,9 @@ def _validate_identifiers(
 
         return list(valid_mpids.union(new_mpids))
 
-    def fetch_many(self, str_idxs: str) -> list[FetchResult]:
+    def fetch_many(
+        self, str_idxs: str, limit_one_per_chemsys: bool = False
+    ) -> list[FetchResult]:
         """Retrieve complete material information for a list of materials.
 
         Should only be used to retrieve at most 100 materials.
@@ -248,6 +250,8 @@ def fetch_many(self, str_idxs: str) -> list[FetchResult]:
             str_idxs (str) : A list of Materials Project IDs,
                 chemical formulas, or chemical systems, separated by
                 commas, e.g., "mp-13, LiCl, Fe-O"
+            limit_one_per_chemsys (bool) : Whether to limit to one
+                entry per chemical system.
 
         Returns:
             list of FetchResult with detailed material metadata.
@@ -263,7 +267,10 @@ def fetch_many(self, str_idxs: str) -> list[FetchResult]:
                 "most 100 identifiers or use `fetch_all` to retrieve all "
                 "data and filter down."
             )
-        idxs = self._validate_identifiers(idxs, limit_one_per_chemsys=True)
+        idxs = self._validate_identifiers(
+            idxs,
+            limit_one_per_chemsys=limit_one_per_chemsys,
+        )
         return self._aggregate_fetch_results_from_mpids(idxs)
 
     def fetch(self, idx: str) -> FetchResult:
@@ -294,7 +301,7 @@ def fetch(self, idx: str) -> FetchResult:
         Raises:
             MPRestError: If no identifier is specified
         """
-        return self.fetch_many(idx)[0]
+        return self.fetch_many(idx, limit_one_per_chemsys=True)[0]
 
     def get_phase_diagram_from_elements(
         self,