# RESNAME error while using cgenff\_charmm2gmx script

**URL:** <https://gromacs.bioexcel.eu/t/resname-error-while-using-cgenff-charmm2gmx-script/7140>\
**Category:** User discussions\
**Tags:** mdrun\
**Created:** [September 7, 2023, 7:52am UTC](https://gromacs.bioexcel.eu/t/resname-error-while-using-cgenff-charmm2gmx-script/7140 "2023-09-07T07:52:31Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![andolesowmya](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/andolesowmya/32/2423_2.png) [@andolesowmya](https://gromacs.bioexcel.eu/u/andolesowmya)\
**Post date:** [September 7, 2023, 7:52am UTC](https://gromacs.bioexcel.eu/t/resname-error-while-using-cgenff-charmm2gmx-script/7140/1 "2023-09-07T07:52:31Z")

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GROMACS version: 2022  
GROMACS modification: Yes/No

Hi, i have the following error, when i’m trying to generate topology for my ligand…  
I’m using Python 3.7.3 and Networkx 2.3, i have updated numpy to correct version.

The code and error:

(py373) C:\Andole\HCU RF\Protein work\Molecular Dynamics Simulation Gromacs\Honokiol\>python cgenff\_charmm2gmx\_py3\_nx2.py Honokiol Honokiol\_fix.mol2 Honokiol.str charmm36-jul2022.ff  
Usage: RESNAME drug.mol2 drug.str charmm36.ff

Please help.

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**Author:** ![Hindol](https://avatars.discourse-cdn.com/v4/letter/h/ecae2f/32.png) [@Hindol](https://gromacs.bioexcel.eu/u/Hindol)\
**Post date:** [May 18, 2025, 9:19am UTC](https://gromacs.bioexcel.eu/t/resname-error-while-using-cgenff-charmm2gmx-script/7140/2 "2025-05-18T09:19:01Z")

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Did you find any solution? I am facing the same issue.