Im trying to get OpenMC to run but im having some issues

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1

I think i have OpenMC installed, when i type in OpenMC in my mac terminal I get the large openMC emblem but i get this error: ERROR: Could not find nuclide O18 in the nuclear data library. Im trying to run the SFR code from the Jupyter nbviewer website. I inputed all the way up to In [23] and this is what i get in my output:

File “/opt/anaconda3/lib/python3.12/site-packages/openmc/model/model.py”, line 151, in is_initialized
import openmc.lib
File “/opt/anaconda3/lib/python3.12/site-packages/openmc/lib/init.py”, line 30, in
_dll = CDLL(str(_filename)) # TODO: Remove str() when Python 3.12+
^^^^^^^^^^^^^^^^^^^^
File “/opt/anaconda3/lib/python3.12/ctypes/init.py”, line 379, in init
self._handle = _dlopen(self._name, mode)
^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: dlopen(/opt/anaconda3/lib/python3.12/site-packages/openmc/lib/libopenmc.dylib, 0x0006): tried: ‘/opt/anaconda3/lib/python3.12/site-packages/openmc/lib/libopenmc.dylib’ (no such file), ‘/System/Volumes/Preboot/Cryptexes/OS/opt/anaconda3/lib/python3.12/site-packages/openmc/lib/libopenmc.dylib’ (no such file), ‘/opt/anaconda3/lib/python3.12/site-packages/openmc/lib/libopenmc.dylib’ (no such file)

im not sure it has something to do with the way i installed openMC, if there is an issue with the data, or if theres a problem with anaconda being involved. any help would be much appreciated.

2

Hi akd27, welcome to the openmc community,
Since you said that the ERROR: Could not find nuclide O18 in the nuclear data library was raised in your case, then I think it come from the nuclear data library being used in your machine. Have you tried to use ENDF/B-VIII.0 instead of ENDF/B-VII.1? You can download it from the official openmc nuclear data site