# Mdp options for umbrella sampling of protein units rotation

**URL:** <https://gromacs.bioexcel.eu/t/mdp-options-for-umbrella-sampling-of-protein-units-rotation/1092>\
**Category:** User discussions\
**Created:** [November 16, 2020, 4:34am UTC](https://gromacs.bioexcel.eu/t/mdp-options-for-umbrella-sampling-of-protein-units-rotation/1092 "2020-11-16T04:34:31Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![yenju](https://avatars.discourse-cdn.com/v4/letter/y/9d8465/32.png) [@yenju](https://gromacs.bioexcel.eu/u/yenju)\
**Post date:** [November 16, 2020, 4:34am UTC](https://gromacs.bioexcel.eu/t/mdp-options-for-umbrella-sampling-of-protein-units-rotation/1092/1 "2020-11-16T04:34:31Z")

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GROMACS version: 2018.4  
GROMACS modification: Yes/No  
Here post your question  
As stated in the title, I want to do umbrella sampling while rotating two protein units at the same time. How can I give the mdp option?  
Is there no need for the enforced rotation option? And do I only need the pulling option?  
Also, Is the angle-axis suitable for pull-coord1-geometry?