Windowed Multipole cross section error - Could not find nuclide Li6 in the nuclear data library

I’m running openmc version 0.13.0 in a conda environment under WSL2 on Windows 11. I’m trying to use the WMP library from Releases · mit-crpg/WMP_Library · GitHub. I followed the steps in the user’s manual and used to register the files.

I know the path I’m entering is valid, and the cross_sections.xml file looks similar to ones that do work.

The problem is similar to post OpenMC not finding multipole library, except that one was resolved by upgrading openmc from 0.10.0 to 0.11.0.

Is the only solution to downgrade to 0.11.0? Or, am I missing a step somewhere?

Thank you in advance for any help resolving this. Brian

@bjl welcome to the community! The latest release of the WMP library should work with any recent version of OpenMC since the format hasn’t changed recently. I’ll note that our official ENDF/B-VII.1 library available here has WMP data included, so if that library is suitable for your purposes you may want to use that.

The error you posted in the title doesn’t sound like an WMP-related error to me though. That error likely indicates that Li6 was not listed in your cross_sections.xml file. To be clear, the WMP data is separate from the normal incident neutron data, so if you’re using WMP data your cross_sections.xml should have two separate entries for Li6, one with type="neutron" and one with type="wmp".

Thank you Paul, I got it working, it appears to have been a file or path corruption problem. I think it was WSL2 related…moving data between the windows file system and the Linux environment. Anyhow, its working now.