move remaining VaspInputGenerator features to PMG

Author: esoteric-ephemera

pymatgen/io/vasp/sets.py

@@ -1122,6 +1122,54 @@ def next_g_size(cur_g_size):
 
         return ng_vec, [ng_ * finer_g_scale for ng_ in ng_vec]
 
+    @staticmethod
+    def from_directory(directory: str | Path, optional_files: dict = None) -> VaspInput:
+        """Load a set of VASP inputs from a directory.
+
+        Note that only the standard INCAR, POSCAR, POTCAR and KPOINTS files are read
+        unless optional_filenames is specified.
+
+        Parameters
+        ----------
+        directory
+            Directory to read VASP inputs from.
+        optional_files
+            Optional files to read in as well as a dict of {filename: Object class}.
+            Object class must have a static/class method from_file.
+        """
+        directory = Path(directory)
+        objs = {"INCAR": Incar, "KPOINTS": Kpoints, "POSCAR": Poscar, "POTCAR": Potcar}
+
+        inputs = {}
+        for name, obj in objs.items():
+            if (directory / name).exists():
+                inputs[name.upper()] = obj.from_file(directory / name)
+            else:
+                # handle the case where there is no KPOINTS file
+                inputs[name.upper()] = None
+
+        optional_inputs = {}
+        if optional_files is not None:
+            for name, obj in optional_files.items():
+                optional_inputs[name] = obj.from_file(directory / name)
+
+        return VaspInput(
+            incar=inputs["INCAR"],
+            kpoints=inputs["KPOINTS"],
+            poscar=inputs["POSCAR"],
+            potcar=inputs["POTCAR"],
+            optional_files=optional_inputs,
+        )
+
+    def _get_nedos(self, dedos: float) -> int:
+        """Automatic setting of nedos using the energy range and the energy step."""
+        if self.prev_vasprun is None:
+            return 2000
+
+        emax = max(eigs.max() for eigs in self.prev_vasprun.eigenvalues.values())
+        emin = min(eigs.min() for eigs in self.prev_vasprun.eigenvalues.values())
+        return int((emax - emin) / dedos)
+
 
 # create VaspInputGenerator alias to follow atomate2 terminology
 VaspInputGenerator = VaspInputSet

tests/io/vasp/test_sets.py

@@ -648,6 +648,32 @@ def test_valid_magmom_struct(self):
             )
             vis.incar.items()
 
+    def test_write_input_and_from_directory(self):
+        structure = Structure.from_spacegroup("Fm-3m",Lattice.cubic(4.),["Fe"],[[0.,0.,0.]])
+
+        vis = self.set(structure=structure)
+        input_set = vis.get_input_set()
+
+        vis.write_input(output_dir=".")
+        assert all(
+            os.path.isfile(file) for file in ("INCAR","KPOINTS","POSCAR","POTCAR")
+        )
+        input_set_from_dir = self.set().from_directory(".")
+
+        assert all(
+            input_set_from_dir[k] == input_set[k] for k in ("INCAR","KPOINTS","POTCAR")
+        )
+        # for some reason the POSCARs are not identical, but their structures and as_dict()'s are
+        assert input_set_from_dir["POSCAR"].structure == input_set["POSCAR"].structure
+        assert input_set_from_dir["POSCAR"].as_dict() == input_set["POSCAR"].as_dict()
+
+    def test_get_nedos(self):
+        vrun = Vasprun(f"{VASP_OUT_DIR}/vasprun.pbesol.xml.gz")    
+        vis = self.set(structure=vrun.structures[-1])
+        # no `prev_vasprun` --> default value of NEDOS
+        assert vis._get_nedos(0.1) == 2000
+        vis.prev_vasprun = vrun
+        assert vis._get_nedos(0.1) == pytest.approx(741,abs=1)
 
 class TestMPStaticSet(PymatgenTest):
     def setUp(self):