# Related to compressing .xtc files

**URL:** <https://gromacs.bioexcel.eu/t/related-to-compressing-xtc-files/3553>\
**Category:** User discussions\
**Created:** [January 27, 2022, 9:51am UTC](https://gromacs.bioexcel.eu/t/related-to-compressing-xtc-files/3553 "2022-01-27T09:51:07Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Akki](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/akki/32/958_2.png) [@Akki](https://gromacs.bioexcel.eu/u/Akki)\
**Post date:** [January 27, 2022, 9:51am UTC](https://gromacs.bioexcel.eu/t/related-to-compressing-xtc-files/3553/1 "2022-01-27T09:51:07Z")

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Can anyone please help me in how to reduce size of my **.xtc files** generated after the SMD simulations… And please let me know, is there any effect on the data in .xtc files, when they are compressed.

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**Author:** ![pjohansson](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/pjohansson/32/316_2.png) [@pjohansson](https://gromacs.bioexcel.eu/u/pjohansson)\
**Post date:** [January 27, 2022, 4:05pm UTC](https://gromacs.bioexcel.eu/t/related-to-compressing-xtc-files/3553/2 "2022-01-27T16:05:47Z")

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Hi,

In my experience there’s almost no value in further compressing trajectories. `.xtc` already is “compressed” by reducing the precision of positions, so some work is done for you with that. You can also decrease the number of frames for further compression using `trjconv`.

If you do want to compress the files yourself more with external tools, it depends on what platform you are using. You can look into the program 7-zip to compress into `.7z`, `.xz`, `.bz2` or `.gz`. These won’t affect your data. But I think you will see very little gain, and large trajectories will take a _lot_ of time to compress/decompress.

Regards,  
Petter

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<div class="post-metadata">

**Author:** ![Akki](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/akki/32/958_2.png) [@Akki](https://gromacs.bioexcel.eu/u/Akki)\
**Post date:** [January 27, 2022, 4:34pm UTC](https://gromacs.bioexcel.eu/t/related-to-compressing-xtc-files/3553/3 "2022-01-27T16:34:18Z")

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Thanks pjohansson for your response… Actually I need compressed data for making Markov state models {MSM}… Do you have any idea, how to do it for that purpose…