Heads up,
While trying to run a depletion case today I ran into repeated segmentation faults as soon as the particle transport started. After a lot of trial and error I finally determined that my one mixed material was causing the issue.
depleted_u = openmc.Material(name='du')
depleted_u.add_element('U',90.0,'wo',enrichment=0.1)
depleted_u.set_density('g/cm3', 19.2)
depleted_u.depletable = True
gad = openmc.Material(name='gad')
gad.add_element('Gd',1,'wo')
gad.set_density('g/cm3', 7.9)
moly = openmc.Material(name='MOLY')
moly.set_density('g/cm3', 10.22)
moly.add_element('Mo', 1.0,'wo')
moly.depletable = True
du_moly = openmc.Material.mix_materials([moly,gad,depleted_u],[0.05,0.05,0.9],'wo',name='DU_10Mo')
This was my original code. I tried turning off depletion for each of the components and then setting the flag for the mixed version and had the same issue. Creating a material from scratch using the three components worked just fine.