Add a handler for kpoint set change error message

src/custodian/vasp/handlers.py

@@ -139,6 +139,7 @@ class VaspErrorHandler(ErrorHandler):
         "auto_nbands": ["The number of bands has been changed"],
         "ibzkpt": ["not all point group operations"],
         "fexcf": ["supplied exchange-correlation table"],
+        "kpt_set_change": ["VASP internal routines have requested a change of the k-point set"],
     }
 
     def __init__(
@@ -776,6 +777,10 @@ def correct(self, directory="./"):
                         UserWarning,
                     )
 
+        if "kpt_set_change" in self.errors:
+            # The error message says to remove NPAR. We will do that.
+            actions.append({"dict": "INCAR", "action": {"_unset": {"NPAR": 0}}})
+
         VaspModder(vi=vi, directory=directory).apply_actions(actions)
         return {"errors": list(self.errors), "actions": actions}
 

tests/files/vasp.kpt_set_change

@@ -0,0 +1,18 @@
+-----------------------------------------------------------------------------
+|                                                                             |
+|     EEEEEEE  RRRRRR   RRRRRR   OOOOOOO  RRRRRR      ###     ###     ###     |
+|     E        R     R  R     R  O     O  R     R     ###     ###     ###     |
+|     E        R     R  R     R  O     O  R     R     ###     ###     ###     |
+|     EEEEE    RRRRRR   RRRRRR   O     O  RRRRRR       #       #       #      |
+|     E        R   R    R   R    O     O  R   R                               |
+|     E        R    R   R    R   O     O  R    R      ###     ###     ###     |
+|     EEEEEEE  R     R  R     R  OOOOOOO  R     R     ###     ###     ###     |
+|                                                                             |
+|     VASP internal routines have requested a change of the k-point set.      |
+|     Unfortunately, this is only possible if NPAR=number of nodes.           |
+|     Please remove the tag NPAR from the INCAR file and restart the          |
+|     calculation.                                                            |
+|                                                                             |
+|       ---->  I REFUSE TO CONTINUE WITH THIS SICK JOB ... BYE!!! <----       |
+|                                                                             |
+ -----------------------------------------------------------------------------

tests/vasp/test_handlers.py

@@ -618,6 +618,13 @@ def test_auto_nbands_bad_parallelization(self) -> None:
         assert "auto_nbands" in dct["errors"]
         assert dct["actions"] == [{"dict": "INCAR", "action": {"_set": {"NBANDS": 64}}}]
 
+    def test_kpt_set_change(self) -> None:
+        handler = VaspErrorHandler("vasp.kpt_set_change")
+        assert handler.check() is True
+        assert handler.correct()["errors"] == ["kpt_set_change"]
+        incar = Incar.from_file("INCAR")
+        assert "NPAR" not in incar
+
 
 class AliasingErrorHandlerTest(PymatgenTest):
     def setUp(self) -> None: