# Free Energy calculation for Protein ligand complex

**URL:** <https://gromacs.bioexcel.eu/t/free-energy-calculation-for-protein-ligand-complex/8902>\
**Category:** User discussions\
**Tags:** analysis-tools\
**Created:** [April 17, 2024, 6:10am UTC](https://gromacs.bioexcel.eu/t/free-energy-calculation-for-protein-ligand-complex/8902 "2024-04-17T06:10:21Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![gsaha322](https://avatars.discourse-cdn.com/v4/letter/g/b3f665/32.png) [@gsaha322](https://gromacs.bioexcel.eu/u/gsaha322)\
**Post date:** [April 17, 2024, 6:10am UTC](https://gromacs.bioexcel.eu/t/free-energy-calculation-for-protein-ligand-complex/8902/1 "2024-04-17T06:10:21Z")

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GROMACS version: 2020  
GROMACS modification: Yes/No  
Here post your question  
I want to calculate the free energy between oleate ligands and a rat liver Fatty Acid Binding Protein. In the GROMACS tutorial, only the methane in water system tutorial is given. Can anyone please help me regarding the free energy calculation of complex systems like protein-ligand complex?