Add tutorial from DFTB+ school 2022

[charlymedrano7]

caculation of spectra, analysis and photoinduced charge transfer

[aradi]

I've made a PR with suggested changes, see https://github.com/charlymedrano7/recipes/pull/1/files

Have a look at at it, and merge into your PR, if you agree.

Otherwise I was wondering, how you obtain the figures with the dipole moment over time in section "Driving electronic dynamics with external fields" (it is not explained in the document). Furthermore, from the user point of perspective, it is also not clear, how the bond length variation figure in "Ehrenfest dynamics" can be obtained. I think, that would need some more explanation.

[charlymedrano7]

Sure! I will take a look.

Regarding your observations, I totally agree. Please take into account that I worked on the tutorial section and then I just updated the format of the previous sections to be consistent. But those sections were done by @cgsanchez some years ago, so I don't know the details about the figures. Maybe he could provide the scripts to obtain them.

[charlymedrano7]

Hi @aradi! This should be ready to merge. Let me know if I need to do anything else.