avogadro2 : Advanced molecule editor and visualizer 2 ( http://www.openchemistry.org/ )
cp2k : Quantum chemistry and solid state physics software package ( https://www.cp2k.org/ )
xcrysden : X-window CRYstalline Structures and DENsities ( http://www.xcrysden.org/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a dev-zero
For Paludis use this rsync : rsync://gentoo.zugaina.org/dev-zero-portage
If you have a problem : ycarus(-at-)zugaina.org