# Protein-Ligand Complex Radius of Gyration Inquiry **URL:** \ **Category:** User discussions\ **Created:** [October 13, 2020, 9:30am UTC](https://gromacs.bioexcel.eu/t/protein-ligand-complex-radius-of-gyration-inquiry/952 "2020-10-13T09:30:38Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![mjsubach](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/mjsubach/32/387_2.png) [@mjsubach](https://gromacs.bioexcel.eu/u/mjsubach)\ **Post date:** [October 13, 2020, 9:30am UTC](https://gromacs.bioexcel.eu/t/protein-ligand-complex-radius-of-gyration-inquiry/952/1 "2020-10-13T09:30:39Z")
GROMACS version: 2020.3 GROMACS modification: Yes/No Here post your question: Hello, I completed the protein-ligand gromacs tutorial, please tell me may I check the Radius of Gyration for this protein or will it in complex skew these results? Much Thanks:) Joel ---
**Author:** ![alevilla](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/alevilla/32/439_2.png) [@alevilla](https://gromacs.bioexcel.eu/u/alevilla)\ **Post date:** [October 13, 2020, 9:44am UTC](https://gromacs.bioexcel.eu/t/protein-ligand-complex-radius-of-gyration-inquiry/952/2 "2020-10-13T09:44:59Z")
Hi, Not sure that I got your question. Anyway to calculate RMSD and Radius of Gyration of acsystem you can use the tools gmx rms and gmx gyrate. You can choose to calculate for only a protein or for a complex (protein+ligand) (using option -n). Kind regards Alessandra ---
**Author:** ![mjsubach](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/mjsubach/32/387_2.png) [@mjsubach](https://gromacs.bioexcel.eu/u/mjsubach)\ **Post date:** [October 13, 2020, 9:46am UTC](https://gromacs.bioexcel.eu/t/protein-ligand-complex-radius-of-gyration-inquiry/952/3 "2020-10-13T09:46:51Z")
Hello ok thanks a bunch:)