/usr/lib/x86_64-linux-gnu/libgromacs.so.2 is in libgromacs2 2016.1-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libgromacs.so.2.1.0
/usr/lib/x86_64-linux-gnu/libgromacs.so.2.1.0