Add configurable PRINT card values to Struct2XAS.make_input_feff

[hcenge]

Motivation

Using Struct2XAS to generate FEFF paths for EXAFS fitting requires the individual feffNNNN.dat files. This requires ff2chi=3 in the PRINT card, but it was hardcoded to 0 in the template file feff_exafs.tmpl.

structure2feff.py already defaults to ff2chi=3, so this change makes struct2xas.py consistent while letting users override if needed.

Changes

• Added feff_print parameter to make_input_feff() (default [1,0,0,0,0,3])
• Updated feff_exafs.tmpl to use placeholders for the feff PRINT output parameters
• Added unit tests in tests/test_struct2xas_feff_print.py

Usage

mat.make_input_feff(radius=7)  # default now outputs feffNNNN.dat files
mat.make_input_feff(radius=7, feff_print=[1,0,0,0,0,0])  # old behavior

Old behavior is recoverable by passing feff_print=[1,0,0,0,0,0]

[maurov]

@hcenge thanks for proposing this improvement. I may merge this, but we are moving all the FEFF/FDMNES input generation to a separate project, Larixite. I have created a task for it #607. In fact, structure2feff and struct2xas are DEPRECATED and will be removed soon from Larch.

Would you be interested in trying Larixite and contribute there?

If yes, please note that larixite.struct2xas, which is a mere copy of larch.xrd.struct2xas should not be used neither. In fact, the idea is to merge the existing code into a common one, as was done for the FDMNES input generation in Larixite. Unfortunately, I did not have the time to do it yet. See Larixite#4.

[newville]

@hcenge @maurov Thanks - I think this would be a very nice addition, and probably best in Larixite.

[hcenge]

@newville @maurov Thanks for the feedback and background information, I will have a go at implementing this in Larixite per Issue#4 there.