Photoemission PR

[wuppersaver]

Dear all,
it has been a long time but we finally managed to get all the things working as expected.

This is the final version of the code with tests and all the functionality necessary, that should be able to be merged into the code.

I undid a lot of my previous commits on the develop branch to not have a messed up git timeline. This also unfortunately deleted the old PR of mine.

[ajm143]

Many thanks for this. I'm currently on shared-parental leave so might be a bit slower than usual.
All the best,
Andrew

[ajm143]

• /src/build.f90 seems to have been committed by mistake. This file is made at compile time.
• Question: What happens (and what should happen) if someone choses TASK: ALL in the odi.
• Add yourself + Nic to Contributors in the user guide.
• User Guide: 5.2.1 requires the photoemission task
• It appears that it requires a devel_code in the CASTEP param file to make it work? What's your timeline for having this properly in CASTEP?

[wuppersaver]

Dear Andrew,

thank you for looking into this! My apologies for getting back to you later, I have been quite busy with family matters recently.

I will submit another commit with the new changes.

• The build.f90 has been removed.
• For now, I have not modified the set of tasks called by 'ALL'. There are a number of photoemission parameters where it is difficult to find sane defaults for (work function, photon energy, mean free path, ... ) and not all the files necessary for the photoemission calculation are currently produced by CASTEP when choosing SPECTRAL_TASK as 'ALL'.
• I have added the people from the project on the second page with a note about photoemission.
  Question: Is that a good place or is there a better one?
  I will also add in the citation for the photoemission module paper once it has been published.
• I have added the task and a short note on the differences between the two modes that are currently implemented.
• I have not yet fully finalised the code for submission to the CASTEP repository, but it is very close, so I hope this can become part of the 26.1 version.