# NOE constrains C-C vs H-H

**URL:** <https://ask.bioexcel.eu/t/noe-constrains-c-c-vs-h-h/6094>\
**Category:** Uncategorized\
**Created:** [April 27, 2026, 8:21am UTC](https://ask.bioexcel.eu/t/noe-constrains-c-c-vs-h-h/6094 "2026-04-27T08:21:17Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![csadim](https://avatars.discourse-cdn.com/v4/letter/c/58956e/32.png) [@csadim](https://ask.bioexcel.eu/u/csadim)\
**Post date:** [April 27, 2026, 8:21am UTC](https://ask.bioexcel.eu/t/noe-constrains-c-c-vs-h-h/6094/1 "2026-04-27T08:21:17Z")

</div>

Hi,

I am calculating a CSP, NOE guided protein/peptide complex. I am getting better results when using heavy atom to heavy atom constrains (only one cluster, lower energy ) than when using H-H constrains.

I have two questions.

Is there a clear disadvantage for using C-C over H-H. (we hope to submit it to the PDB somtime)

Is there a way to know if a constrain was ignored during the calculation maybe due to wrong nami ng?