For anyone reading this in the future, an alternative if you can’t get this to work either is to use the following code:
results = openmc.deplete.Results(‘depletion_results.h5’)
materials_dep = results.export_to_materials(1) # 1 is for 1 step depletion, 0 would be fresh
materials_dep.export_to_xml()
This generates a new materials.xml file containing the depleted materials which can be used to check compositions. There are some quirks to using this though, primarily the “atomic percents” listed in the compositions don’t add to 1 or anything close to it for the depleted materials. The values are consistently arbitrary.