# Angle calculation by gmx gangle

**URL:** https://gromacs.bioexcel.eu/t/angle-calculation-by-gmx-gangle/8412
**Category:** User discussions
**Tags:** analysis-tools
**Created:** [February 23, 2024, 5:58pm UTC](https://gromacs.bioexcel.eu/t/angle-calculation-by-gmx-gangle/8412 "2024-02-23T17:58:27Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![maham](https://avatars.discourse-cdn.com/v4/letter/m/c77e96/32.png) [@maham](https://gromacs.bioexcel.eu/u/maham)
#### Post date: [February 23, 2024, 5:58pm UTC](https://gromacs.bioexcel.eu/t/angle-calculation-by-gmx-gangle/8412/1 "2024-02-23T17:58:27Z")

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I have a protein and I want to check the orientation of side chain of a particular resdiue with respect to the residue in the active site. any help on this regard? currently I am using gmx gangel where the group 1 includes the alpha carbon position of active side residue and alpha carbon of the other residue and group 2 include alpha carbon of active residue and the last atom of the other residue. i am not sure if this is the correct way. any guidance would be appreciated.