# There was an error in rigid body stage of the docking

**URL:** <https://ask.bioexcel.eu/t/there-was-an-error-in-rigid-body-stage-of-the-docking/1817>\
**Category:** HADDOCK\
**Created:** [February 7, 2020, 7:58pm UTC](https://ask.bioexcel.eu/t/there-was-an-error-in-rigid-body-stage-of-the-docking/1817 "2020-02-07T19:58:05Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Diana\_Cudia](https://avatars.discourse-cdn.com/v4/letter/d/7ab992/32.png) [@Diana\_Cudia](https://ask.bioexcel.eu/u/Diana_Cudia)\
**Post date:** [February 7, 2020, 7:58pm UTC](https://ask.bioexcel.eu/t/there-was-an-error-in-rigid-body-stage-of-the-docking/1817/1 "2020-02-07T19:58:05Z")

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Dear Haddock users,

I have recently submitted a metal-protein docking calculation; however, it resulted in an error. I am following the steps a former post-doc has done to achieve this dimerization model using the same Fe2+ PDB file. First, he docked Fe2+ to a monomer with unambiguous distance restraints. He was able to move forward and dock another monomer to produce the dimer.

My attempts have been failing and I’m not sure why. Below is the link of the output file error:

[http://milou.science.uu.nl/serviceresults/HADDOCK2.2/6154977781/fe-monomer-cys15cys175/complex\_run1\_it0\_refine\_1.out](http://milou.science.uu.nl/serviceresults/HADDOCK2.2/6154977781/fe-monomer-cys15cys175/complex_run1_it0_refine_1.out)

" \*\*\*\*\* WARNING \*\*\*\*\* FROM ORINTC. ROTATION MATRIX IS NOT UNITARY.  
DETERMINANT= -1.00000000" – this was found at the bottom of the file.

How may I correct this error?

Thanks for the help!  
Diana

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<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:** [February 9, 2020, 4:10pm UTC](https://ask.bioexcel.eu/t/there-was-an-error-in-rigid-body-stage-of-the-docking/1817/2 "2020-02-09T16:10:15Z")

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The cause of the failure is another one. Check the FAILED file on the web page:

```auto
TOTAL NUMBER OF DISTANCE RESTRAINTS FOR RIGID BODY DOCKING IS ZERO!
CONTROL YOUR PARAMETER SETTINGS AND RESTRAINT DEFINITIONS
STRUCTURE NUMBER 201

```

Something is thus wrong in the way you defined the restraints to the iron.

Note that if you used the atom name in your restraints, you will have to put it between “ “ because of the + in the name