Getting large ripples for S(Q) from current implementation of DiffPy DebyePDFCalculator

Getting following issues in S(Q)

Issues:

• ripples in data

This might be a known error based on this DiffPy Google Group discussion:

• https://groups.google.com/g/diffpy-users/c/QSMAjTFFH5o?pli=1
• In that, looks like Niklas Thompson mentions fix to this bug

  For anyone interested, I think the coupling between rmax and qstep is due to automatic initialization of the 'setOptimumQstep' option, and can be overridden by setting qstep manually.

Also, it looks like the DebyeCalculator code base has a utility that might have this fix already implemented (I have not tried it yet)

• https://github.com/FrederikLizakJohansen/DebyeCalculator/blob/main/debyecalculator/utility/SASCalculator.py#L15-L99

TODOs:

• Try to fix using Niklas's ideas for setting qstep
• Also, try out the DebyeCalculator SASCalculator utility