How to remove duplicate frames

User discussions
1

GROMACS version: 2026.1
GROMACS modification: No

I have a multi-part production trajectory split into 4 parts (part1–part4). When merging with gmx trjcat, parts 2 and 3 had the same start time (608300 ps) due to a resubmitted run after a crash. My goal is to merge the xtc files and remove duplicate frames.

Should I do gmx trjcat -f part1.xtc part2.xtc part3.xtc part4.xtc -o merged.xtc
Should I include the -cat option?

Best regards

2

From the manual page,

“In case of double time frames the one in the later file is used. […] Using -cat, you can simply paste several files together without removal of frames with identical time stamps.”

So, the command you included should work just fine, without the -cat option.

3

Thank you!