diff --git a/openmc/universe.py b/openmc/universe.py index 78f75bbfc1..7dee19313a 100644 --- a/openmc/universe.py +++ b/openmc/universe.py @@ -334,6 +334,13 @@ class Universe(UniverseBase): if seed is not None: model.settings.seed = seed + # Determine whether any materials contains macroscopic data and if + # so, set energy mode accordingly + for mat in self.get_all_materials().values(): + if mat._macroscopic is not None: + model.settings.energy_mode = 'multi-group' + break + # Create plot object matching passed arguments plot = openmc.Plot() plot.origin = origin