Trouble with O16 cross section

User Support
1

Hello,

When I try to run openmc I get this output:

<normal # % ball of openmc fun>
Reading settings XML file…

Reading cross sections XML file…

Reading materials XML file…

Reading geometry XML file…

Reading O16 from /home/*******/endfb71_hdf5/O16.h5

ERROR: Nuclear data library does not contain cross sections for O16 at or near 920.000000 K.

Thus I tried manually generating the O16.h5 file from ACE files as described in the documentation to ensure this temperature range is covered (although it should be covered normally from what I downloaded from https://openmc.org/official-data-libraries/). However I still get the same error. This occurs on both the developer branch and the master branch.

Does anyone have any idea what might be up?

Thanks so much and I hope everyone and their families are hanging in there!

2

Hi Percy,

By default, OpenMC will use the temperatures you specify in the problem to look for cross sections at the nearest temperature. If it doesn’t find cross sections at (or close to) those temperatures, you’ll get this error message. If you want to interpolate between two temperatures, you need to specify this explicitly:

settings = openmc.Settings()
settings.temperature = {‘method’: ‘interpolation’}
…

Hope this helps!

Best,
Paul

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