Overhaul the system normalizer
- required by optimade api #205 (closed)
- related to missing geometry metric #204 (closed)
The current system normalizer is only run for one system. It is ok to only perform the costly system and symmetry classification for a few systems, but some things should be normalized for all systems:
- atoms
- species
- hill, full, reduced
- lattice, positions, PBC
Furthermore, the normalizer and metainfo does really account for
- the difference between sites and elements, i.e. atoms and species
- different versions of the same element in different sites (species?), e.g. Na and Na2
Some things are missing:
- nelements vs. nsites
- element concentrations