/usr/share/gromacs/top/amber94.ff/ is in gromacs-data 2018.1-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/gromacs/top/amber94.ff/aminoacids.arn
/usr/share/gromacs/top/amber94.ff/aminoacids.c.tdb
/usr/share/gromacs/top/amber94.ff/aminoacids.hdb
/usr/share/gromacs/top/amber94.ff/aminoacids.n.tdb
/usr/share/gromacs/top/amber94.ff/aminoacids.r2b
/usr/share/gromacs/top/amber94.ff/aminoacids.rtp
/usr/share/gromacs/top/amber94.ff/aminoacids.vsd
/usr/share/gromacs/top/amber94.ff/atomtypes.atp
/usr/share/gromacs/top/amber94.ff/dna.arn
/usr/share/gromacs/top/amber94.ff/dna.hdb
/usr/share/gromacs/top/amber94.ff/dna.r2b
/usr/share/gromacs/top/amber94.ff/dna.rtp
/usr/share/gromacs/top/amber94.ff/ffbonded.itp
/usr/share/gromacs/top/amber94.ff/ffnonbonded.itp
/usr/share/gromacs/top/amber94.ff/forcefield.doc
/usr/share/gromacs/top/amber94.ff/forcefield.itp
/usr/share/gromacs/top/amber94.ff/gbsa.itp
/usr/share/gromacs/top/amber94.ff/ions.itp
/usr/share/gromacs/top/amber94.ff/rna.arn
/usr/share/gromacs/top/amber94.ff/rna.hdb
/usr/share/gromacs/top/amber94.ff/rna.r2b
/usr/share/gromacs/top/amber94.ff/rna.rtp
/usr/share/gromacs/top/amber94.ff/spc.itp
/usr/share/gromacs/top/amber94.ff/spce.itp
/usr/share/gromacs/top/amber94.ff/tip3p.itp
/usr/share/gromacs/top/amber94.ff/tip4p.itp
/usr/share/gromacs/top/amber94.ff/tip4pew.itp
/usr/share/gromacs/top/amber94.ff/tip5p.itp
/usr/share/gromacs/top/amber94.ff/urea.itp
/usr/share/gromacs/top/amber94.ff/watermodels.dat