Check common symmetries in Geometry and Grid

[pfebrer]

Yet another new issue :) I'm just dropping ideas as they come to my mind so that they stay here as possible things to do. I hope you don't mind.

In this case, it is about simmetry. I believe it could be useful to provide a quick way for users to check if a Geometry or a Grid fulfills a common simmetry (i.e. mirror planes and inversion axes that follow cell axes, inversion center...). Some of them seem easy to check (the mirror plane, for example), but still some extra things need to be taken into account (if the plane is not centered in the unit cell, for example).

What do you think? It could be very cool to be able to do something like:

grid.symmetry.has_mirror_plane(z=2)

to check the simmetry of wavefunctions for example.

Note: For geometries we could take advantage of the spglib package https://atztogo.github.io/spglib/python-spglib.html which already implements finding simmetry operations and determining space groups. So, we would only need a converter from Geometry to their cell data structure. (ASE uses the spglib package here https://wiki.fysik.dtu.dk/ase/ase/spacegroup/spacegroup.html)

Cheers!

[zerothi]

No, good with ideas.

And yeah. Symmetries have always been interesting. I just don't have the time. :( I think the symmetries would go under the attr section #196 to not stuff Geomtry with too much. But ideas to keep in mind:

• [ ] spglib
• [ ] SeekPath
• others?