This is a latex-package used for typesetting isotopes, i.e. chemical symbol with atomic mass and atomic number attached to it (with normal latex-math-mode it does not really look good.). I think it's dev-tex (is it)
Created attachment 98237 [details] isotope-1.0.0.ebuild
I have been using this for my thesis, didn't spot your ebuild initially. Used an adapted version of it - added it in CVS. Thanks for your work.