/usr/share/man/man1/gchem3d-0.14.1.gz is in gcu-bin 0.14.6-1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/man/man1/gchem3d.1.gz
/usr/share/man/man1/gchem3d.1.gz