Allowing material making from class constructor

openmc/material.py

@@ -60,6 +60,18 @@ class Material(IDManagerMixin):
     temperature : float, optional
         Temperature of the material in Kelvin. If not specified, the material
         inherits the default temperature applied to the model.
+    density : float, optional
+        Density of the material (units defined separately)
+    density_units : str
+        Units used for `density`. Can be one of 'g/cm3', 'g/cc', 'kg/m3',
+        'atom/b-cm', 'atom/cm3', 'sum', or 'macro'.  The 'macro' unit only
+        applies in the case of a multi-group calculation.
+    depletable : bool, optional
+        Indicate whether the material is depletable. Defaults to False.
+    volume : float, optional
+        Volume of the material in cm^3. This can either be set manually or
+        calculated in a stochastic volume calculation and added via the
+        :meth:`Material.add_volume_information` method.
 
     Attributes
     ----------
@@ -111,17 +123,26 @@ class Material(IDManagerMixin):
     next_id = 1
     used_ids = set()
 
-    def __init__(self, material_id=None, name='', temperature=None):
+    def __init__(
+        self,
+        material_id: int | None = None,
+        name: str = "",
+        temperature: float | None = None,
+        density: float | None = None,
+        density_units: str | None = None,
+        depletable: bool | None = False,
+        volume: float | None = None,
+    ):
         # Initialize class attributes
         self.id = material_id
         self.name = name
         self.temperature = temperature
         self._density = None
         self._density_units = 'sum'
-        self._depletable = False
+        self._depletable = depletable
         self._paths = None
         self._num_instances = None
-        self._volume = None
+        self._volume = volume
         self._atoms = {}
         self._isotropic = []
         self._ncrystal_cfg = None
@@ -136,6 +157,17 @@ def __init__(self, material_id=None, name='', temperature=None):
         # If specified, a list of table names
         self._sab = []
 
+        # Set density if provided
+        if (density is not None and density_units is None) or (
+            density is None and density_units is not None
+        ):
+            raise ValueError(
+                "Both density and density_units must be provided together."
+            )
+        elif density is not None and density_units is not None:
+            self.set_density(density_units, density)
+
+
     def __repr__(self) -> str:
         string = 'Material\n'
         string += '{: <16}=\t{}\n'.format('\tID', self._id)

tests/unit_tests/test_material.py

@@ -767,3 +767,34 @@ def test_mean_free_path():
     mat2.add_nuclide('Pb208', 1.0)
     mat2.set_density('g/cm3', 11.34)
     assert mat2.mean_free_path(energy=14e6) == pytest.approx(5.65, abs=1e-2)
+
+
+def test_material_from_constructor():
+
+    mat1 = openmc.Material(
+        **{
+            "material_id": 1,
+            "name": "neutron_star",
+            "density": 1e17,
+            "density_units": "kg/m3",
+        }
+    )
+    assert mat1.id == 1
+    assert mat1.name == "neutron_star"
+    assert mat1._density == 1e17
+    assert mat1._density_units == "kg/m3"
+    assert mat1.nuclides == []
+
+    mat2 = openmc.Material(
+        material_id=42,
+        name="plasma",
+        temperature=None,
+        density=1e-7,
+        density_units="g/cm3",
+    )
+    assert mat2.id == 42
+    assert mat2.name == "plasma"
+    assert mat2.temperature is None
+    assert mat2.density == 1e-7
+    assert mat2.density_units == "g/cm3"
+    assert mat2.nuclides == []