Problem with Thermal scattering

I try to modeling mix of para-H and ortho-H. For them I need thermal scattering data. But I can’t do it. They’re liquid, so I can’t make two materials. In add_s_alpha_beta() there is some parameter called fraction. In annotation wrote that it can help for mix, when one of them have TSD, and other - not , but it doesn’t work when two of them have TSD. Maybe I do something wrong?

Hi @Ilyavitte! Unfortunately what you are trying to do is not currently supported. As you have discovered, you can specify some fraction of a nuclide to use S(a,b) and some fraction to not, but you cannot mix two S(a,b) tables that apply to the same nuclides right now.

Ok, thank you. So how i can make mix with 90%para-H and 10%ortho-H ?