add option to approx neb common maker to specify different endpoint relax maker

Author: esoteric-ephemera

src/atomate2/common/flows/approx_neb.py

@@ -35,8 +35,12 @@ class CommonApproxNebMaker(Maker):
         Name of the workflow
     host_relax_maker : Maker
         Optional, a maker to relax the input host structure.
-    image_relax_maker : maker
+    image_relax_maker : Maker
         Required, a maker to relax the ApproxNEB endpoints and images.
+    endpoint_relax_maker : Maker or None (default)
+        Optional maker to relax the endpoints that could differ from the
+        relax maker used on the intermediate images.
+        If None, this is set to `image_relax_maker`.
     selective_dynamics_scheme : "fix_two_atoms" (default) or None
         If "fix_two_atoms", uses the default selective dynamics scheme of ApproxNEB,
         wherein the migrating ion and the ion farthest from it are the only
@@ -51,6 +55,7 @@ class CommonApproxNebMaker(Maker):
     name: str = "ApproxNEB"
     host_relax_maker: Maker | None = None
     image_relax_maker: Maker = None
+    endpoint_relax_maker: Maker | None = None
     selective_dynamics_scheme: Literal["fix_two_atoms"] | None = "fix_two_atoms"
     min_hop_distance: float | bool = True
 
@@ -114,7 +119,7 @@ def make(
             working_ion=working_ion,
             endpoint_coords=inserted_coords_dict,
             inserted_coords_combo=inserted_coords_combo,
-            relax_maker=self.image_relax_maker,
+            relax_maker=self.endpoint_relax_maker or self.image_relax_maker,
         )
 
         # run pathfinder (and selective dynamics) to get image structure input