# RDF analysis of multiple proteins

**URL:** <https://gromacs.bioexcel.eu/t/rdf-analysis-of-multiple-proteins/2584>\
**Category:** User discussions\
**Tags:** analysis-tools\
**Created:** [July 23, 2021, 11:48am UTC](https://gromacs.bioexcel.eu/t/rdf-analysis-of-multiple-proteins/2584 "2021-07-23T11:48:37Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![azadeh](https://avatars.discourse-cdn.com/v4/letter/a/cab0a1/32.png) [@azadeh](https://gromacs.bioexcel.eu/u/azadeh)\
**Post date:** [July 23, 2021, 11:48am UTC](https://gromacs.bioexcel.eu/t/rdf-analysis-of-multiple-proteins/2584/1 "2021-07-23T11:48:37Z")

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GROMACS version: 2019  
GROMACS modification: No

Dear GROMACS users,

In my system I have several proteins (similar), which have the same resid number (every similar residue on each protein have the same resid number). I would like to use the RDF analysis tool and calculate the RDF of the center of mass of the proteins.

In the analysis command I set the -sel and -ref flags to the resids of the proteins (which is the same for all proteins) and -selrpos and -seltype to “whole\_mol\_com”. I was wondering whether this is correct.

Thank you very much for your help.

Best regards,  
Azadeh