This package is not actively maintained in Gentoo. The explicit maintainer (alexxy) resigned from it in Mar 2016. The last maintainer commit was a version bump in Jul 2013. Since then, there were only non-maintainer fixes to the ebuild, mostly in regard to dependencies and multilib. The package is proprietary and fetch-restricted (requires a license to download). From what I've been able to find in the manual [1], the current Gentoo version is outdated, and the package seems to be actively maintained upstream. The package has a number of QA issues which nobody seemed interested in addressing so far. [1]:http://www.molsoft.com/icmpro/
commit 668ec1f0924a56d76d4ce1e82711837e5ec83c73 Author: Michał Górny <mgorny@gentoo.org> AuthorDate: Mon Aug 14 23:31:51 2017 Commit: Michał Górny <mgorny@gentoo.org> CommitDate: Mon Aug 14 23:39:15 2017 sci-chemistry/icm: Remove last-rited pkg, #622414
