/usr/share/gromacs/top/charmm27.ff/ is in gromacs-data 4.5.5-2.
This file is owned by root:root, with mode 0o755.
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/usr/share/gromacs/top/charmm27.ff/aminoacids.arn
/usr/share/gromacs/top/charmm27.ff/aminoacids.c.tdb
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