Add ElectronicEigenvalues and ElectronicBandStructure properties

[JosePizarro3]

This pr contains the definition for the former ElectronicBandStructure with the new schema (PhysicalProperties and Variables), as well as the new property ElectronicEigenvalues. During development, I also wanted to define FermiSurface, but this makes more sense in a separate pr (#78).

Some important changes with respect to the old schema and normalization:

• Now, there is a value_contributions whose objective is to group all the former stuff that was in BandEnergies as value_<name-of-the-contribution>
• Now there is not a concept of segments. I rather changed for storing KLinePath(Variables).points as a flat list of points
• I completely restructured the old add_band_gap normalization. Now, we have extract_band_gap and, mainly, resolve_homo_lumo_eigenvalues to handle this.
• The old get_special_points function is re-defined under numerical_settings.py:KMesh. This was a very buggy function, specially when the path is not defined for points related by symmetry (e.g., 'X' is both [0.5, 0, 0] and [-0.5, 0, 0]. Now we aim people to define the strings related with the high symmetry points OR manually define the path.

One question is whether reciprocal_cell will be still here in this schema or we can resolve it in another way. This quantity is only interesting for the front end.

[coveralls]

Pull Request Test Coverage Report for Build 9347862591

Details

• 139 of 140 (99.29%) changed or added relevant lines in 8 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.07%) to 98.681%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
tests/conftest.py	20	21	95.24%

Totals
Change from base Build 9269679463:	0.07%
Covered Lines:	898
Relevant Lines:	910

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💛 - Coveralls

[JosePizarro3]

Hey @ladinesa this is the pr I told you about.

The focus should be the changes in the new module, src/nomad_simulations/properties/band_structure.py. I still have some todos, but I moved them to separated issues (#77 #78 #79).

Thanks!

[ladinesa]

Looks all fine to me except for some minor improvements. Do I check also the tests?

[JosePizarro3]

Looks all fine to me except for some minor improvements. Do I check also the tests?

Thanks! I think the tests are just there to help understand the code, so up to you. Coverage is 99% (whatever that means 😅), so I guess I did a good job.

[JosePizarro3]

Ok, this pr is ready. I added also a validator for comparing a quantity with respect to value in any PhysicalProperty, to ensure consistence in all the cases where we don't want to consider a quantity a physical property, but to be actually under an existing one.

Thanks for the review @ladinesa @ndaelman-hu ! 🥳