/usr/lib/x86_64-linux-gnu/parmetis-long/libparmetis.so is in libscotchparmetis-dev 6.0.4.dfsg1-8.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/parmetis-long/../scotch-long/libptscotchparmetis.so