/usr/lib/x86_64-linux-gnu/libfmpich.so.12 is in libmpich12 3.1-5+b2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libfmpich.so.12.0.0
/usr/lib/x86_64-linux-gnu/libfmpich.so.12.0.0