"All GROMACS programs can read compressed or g-zipped files. There "
"might be a problem with reading compressed [TT].xtc[tt], "
- "[TT].trr[tt] and [TT].trj[tt] files, but these will not compress "
+ "[TT].trr[tt] files, but these will not compress "
"very well anyway.",
"Most GROMACS programs can process a trajectory with fewer atoms than "