Fix TestMPStaticSet using MPRelaxSet in test_user_incar_kspacing and test_kspacing_override (#3268)

* fix TestMPStaticSet running with MPRelaxSet instead of MPStaticSet in test_user_incar_kspacing and test_kspacing_override

* add self.set attribute to InputSetTests to make it harder to use the wrong InputSet in a test

* fix outdated ValueError msg in PotcarSingle.from_symbol_and_functional

or you may need to set PMG_DEFAULT_FUNCTIONAL to PBE_52 or PBE_54 if you are using newer psps from VASP.

Author: janosh

pymatgen/io/vasp/inputs.py

@@ -1882,18 +1882,17 @@ def from_symbol_and_functional(symbol: str, functional: str | None = None):
         if d is None:
             raise ValueError(
                 f"No POTCAR for {symbol} with {functional=} found. Please set the PMG_VASP_PSP_DIR "
-                "environment in .pmgrc.yaml, or you may need to set PMG_DEFAULT_FUNCTIONAL to PBE_52 or "
-                "PBE_54 if you are using newer psps from VASP."
+                "environment in .pmgrc.yaml."
             )
         paths_to_try = [
             os.path.join(d, funcdir, f"POTCAR.{symbol}"),
             os.path.join(d, funcdir, symbol, "POTCAR"),
         ]
-        for p in paths_to_try:
-            p = os.path.expanduser(p)
-            p = zpath(p)
-            if os.path.exists(p):
-                return PotcarSingle.from_file(p)
+        for path in paths_to_try:
+            path = os.path.expanduser(path)
+            path = zpath(path)
+            if os.path.isfile(path):
+                return PotcarSingle.from_file(path)
         raise OSError(
             f"You do not have the right POTCAR with {functional=} and label {symbol} "
             f"in your VASP_PSP_DIR. Paths tried: {paths_to_try}"

tests/core/test_surface.py

@@ -39,20 +39,15 @@ def setUp(self):
             ["Ti", "Ti", "Ti"],
             [
                 [0, 0, 0],
-                [0.333333, 0.666667, 0.500000],
-                [0.666667, 0.333333, 0.500000],
+                [0.333333, 0.666667, 0.5],
+                [0.666667, 0.333333, 0.5],
             ],
         )
 
         Ag_fcc = Structure(
             Lattice.cubic(4.06),
             ["Ag", "Ag", "Ag", "Ag"],
-            [
-                [0, 0, 0],
-                [0, 0.500000, 0.500000],
-                [0.500000, 0, 0.500000],
-                [0.500000, 0.500000, 0],
-            ],
+            [[0, 0, 0], [0, 0.5, 0.5], [0.5, 0, 0.5], [0.5, 0.5, 0]],
         )
 
         m = [[3.913449, 0, 0], [0, 3.913449, 0], [0, 0, 5.842644]]