New version 4.0 is available http://sourceforge.net/projects/psicode/
Its still beta isn't it?
Psi change its name to psi4 and psi4-1.0 was released at 5 Jul 2016: https://github.com/psi4/psi4/releases/tag/1.0
The difficulty here is a build system that wants to fetch dependencies from the internet (and some dependencies which are not yet packaged in ::gentoo)