Update openforcefield/utils/toolkits.py

Co-Authored-By: Matt Thompson <[email protected]>

openforcefield/utils/toolkits.py

@@ -500,9 +500,7 @@ def to_file(self, molecule, file_path, file_format):
         # Remove all but the first conformer when writing to SDF as we only support single conformer format
         if (file_format.lower() == "sdf") and oemol.NumConfs() > 1:
             conf1 = [conf for conf in oemol.GetConfs()][0]
-            flat_coords = list()
-            for idx, coord in conf1.GetCoords().items():
-                flat_coords.extend(coord)
+            flat_coords = [*conf1.GetCoords().values()]
             oemol.DeleteConfs()
             oecoords = oechem.OEFloatArray(flat_coords)
             oemol.NewConf(oecoords)