Total atomic density for depletion products

Dear experts @paulromano @Shimwell @pshriwise @sourena , I am Openmc, how can I calculate the total atomic concentration of the material after depletion?“results.get_atoms” How can I get the total atomic density from this script? Or what script should I add to the input file to calculate the total atomic density of any nuclide? My aim is to obtain the total atomic density of nuclides in the consumption of mixed fuels and to observe the total change.