# Finding of C-alpha C-alpha distance in Restraints file in Tutorial

**URL:** <https://ask.bioexcel.eu/t/finding-of-c-alpha-c-alpha-distance-in-restraints-file-in-tutorial/4893>\
**Category:** DISVIS\
**Created:** [March 30, 2024, 6:27pm UTC](https://ask.bioexcel.eu/t/finding-of-c-alpha-c-alpha-distance-in-restraints-file-in-tutorial/4893 "2024-03-30T18:27:05Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Devid](https://avatars.discourse-cdn.com/v4/letter/d/22d042/32.png) [@Devid](https://ask.bioexcel.eu/u/Devid)\
**Post date:** [March 30, 2024, 6:27pm UTC](https://ask.bioexcel.eu/t/finding-of-c-alpha-c-alpha-distance-in-restraints-file-in-tutorial/4893/1 "2024-03-30T18:27:05Z")

</div>

Dear all  
I was going through the tutorial for submission of job in DisVis. But I did not understant the C-alpha C-alpha distance that have been taken as 23. I have gone through the link given and read that paper but I did understand the same.Can any one help me such that how it was taken.  
Forgive me as I am new in this field.

---

<div class="post-metadata">

**Author:** ![amjjbonvin](https://dub1.discourse-cdn.com/flex013/user_avatar/ask.bioexcel.eu/amjjbonvin/32/23_2.png) [@amjjbonvin](https://ask.bioexcel.eu/u/amjjbonvin)\
**Post date:** [April 2, 2024, 12:38pm UTC](https://ask.bioexcel.eu/t/finding-of-c-alpha-c-alpha-distance-in-restraints-file-in-tutorial/4893/2 "2024-04-02T12:38:40Z")

</div>

The exact distance will depend on the type of cross-linker used.  
And there is an addition correction added to that distance to account for the fact we used the CA atom (which is not where the cross-linker is attached).