/usr/share/avogadro/fragments/thiols/ is in avogadro-data 1.2.0-1+deb9u1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/avogadro/fragments/thiols/2-methylproprane-2-thiol.cml
/usr/share/avogadro/fragments/thiols/R_butane-2-thiol.cml
/usr/share/avogadro/fragments/thiols/butane-1-thiol.cml
/usr/share/avogadro/fragments/thiols/ethane-1_2-dithiol.cml
/usr/share/avogadro/fragments/thiols/ethanethiol.cml
/usr/share/avogadro/fragments/thiols/heptane-1-thiol.cml
/usr/share/avogadro/fragments/thiols/hexane-1-thiol.cml
/usr/share/avogadro/fragments/thiols/methanethiol.cml
/usr/share/avogadro/fragments/thiols/octane-1-thiol.cml
/usr/share/avogadro/fragments/thiols/pentane-1-thiol.cml
/usr/share/avogadro/fragments/thiols/proprane-1-thiol.cml
/usr/share/avogadro/fragments/thiols/proprane-2-thiol.cml