Add support for use_structure_charge keyword in FHI-aims input gene…

…rator (#4111)

src/pymatgen/io/aims/sets/base.py

@@ -186,10 +186,14 @@ class AimsInputGenerator(InputGenerator):
             parameters for the FHI-aims calculator
         user_kpoints_settings (dict[str, Any]):  The settings
             used to create the k-grid parameters for FHI-aims
+        use_structure_charge (bool): If set to True, then the overall charge of the
+            structure (structure.charge) is used to set the `charge` variable in the
+            `control.in`. Default is False.
     """
 
     user_params: dict[str, Any] = field(default_factory=dict)
     user_kpoints_settings: dict[str, Any] = field(default_factory=dict)
+    use_structure_charge: bool = False
 
     def get_input_set(
         self,
@@ -321,6 +325,9 @@ def _get_input_parameters(
 
         parameter_updates = self.get_parameter_updates(structure, prev_parameters)
         params = recursive_update(params, parameter_updates)
+        # Add the structure charge (useful for defect workflows)
+        if self.use_structure_charge:
+            params["charge"] = structure.charge
 
         # Override default parameters with user_params
         params = recursive_update(params, self.user_params)

tests/io/aims/sets/test_static_generator.py

@@ -16,6 +16,17 @@ def test_static_si(tmp_path):
     comp_system(Si, parameters, "static-si", tmp_path, REF_PATH, StaticSetGenerator)
 
 
+def test_static_o2_charge(tmp_path):
+    parameters = {
+        "species_dir": "light",
+        "k_grid": [2, 2, 2],
+    }
+    Si.set_charge(1)
+    generator = StaticSetGenerator(parameters, use_structure_charge=True)
+    input_set = generator.get_input_set(Si)
+    assert "charge                             1" in input_set.control_in
+
+
 def test_static_si_no_kgrid(tmp_path):
     parameters = {"species_dir": "light"}
     Si_supercell = Si.make_supercell([1, 2, 3], in_place=False)