Paper comments
to largely disregard the effect of core electrons
Apologies for being pedantic, but core electron effects are not disregarded. It's just that their influence is transmitted indirectly via the pseudopotential. You could say "to avoid explicit treatment of core electrons" or similar.
A generalization to other codes with atom-centered basis functions is straight forward.
Since only FHIaims has been used thus far, I think you should replace "is" with "should be".
Statement of need
This section begins rather abruptly. I think you should add an introductory sentence or two (or move something from elsewhere to the beginning of this section) to highlight the broader purpose of CC-aims.
Edited by Chuck Witt