Hierarchical implementation of splittings

[lemmatum]

Make splittings obvious and easily accessible, probably through a hierarchical data structure.
Electron configurations -> LS terms (term structure) -> LSJ levels (Fine structure) -> F (Hyperfine structure)

So given an electron configuration we can list (permute) all possible terms. Given a term structure, list all possible fine structure splittings. Given a fine structure, list all possible hyperfine structure splittings.