I am not able to reproduce your error on my Windows 10 machine. I have run it in command line as follows:
atkpython.exe seebeck_coefficient.py Device_New_Configuration.nc
or through the Job Manager, but in this case you have to replace nc (in nlread in the script) with 'Device_New_Configuration.nc '. So, I had no issue with execution of the script.
Are you running on Windows or Linux? Did you really use the python script and nc-file from the zip-archive posted on Forum or your own nc file?