# Getting error when converting the files using cgenff\_charmm2gmx.py code

**URL:** <https://gromacs.bioexcel.eu/t/getting-error-when-converting-the-files-using-cgenff-charmm2gmx-py-code/12464>\
**Category:** User discussions\
**Created:** [July 30, 2025, 1:47pm UTC](https://gromacs.bioexcel.eu/t/getting-error-when-converting-the-files-using-cgenff-charmm2gmx-py-code/12464 "2025-07-30T13:47:46Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![EhtishamRasool](https://avatars.discourse-cdn.com/v4/letter/e/8c91f0/32.png) [@EhtishamRasool](https://gromacs.bioexcel.eu/u/EhtishamRasool)\
**Post date:** [July 30, 2025, 1:47pm UTC](https://gromacs.bioexcel.eu/t/getting-error-when-converting-the-files-using-cgenff-charmm2gmx-py-code/12464/1 "2025-07-30T13:47:46Z")

</div>

[sukin806@nesh-login1 pyruvate\_in\_water]$ python cgenff\_charmm2gmx.py PYRUVATE pyruvate.mol2 pyruvate.str charmm36.ff  
NOTE 1: Code tested with Python 3.13. Your version: 3.11.5 (main, Nov 7 2023, 15:49:38) [GCC 12.3.0]

NOTE 2: Code tested with NetworkX 3.4.2. Your version: 3.5

NOTE 3: Please be sure to use the same version of CGenFF in your simulations that was used during parameter generation:  
–Version of CGenFF detected in pyruvate.str : 4.6  
–Version of CGenFF detected in charmm36.ff/forcefield.doc : 4.1

WARNING: CGenFF versions are not equivalent!

NOTE 4: To avoid duplicated parameters, do NOT select the ‘Include parameters that are already in CGenFF’ option when uploading a molecule into CGenFF.  
Traceback (most recent call last):  
File “/gxfs\_home/cau/sukin806/Projects/GROMACS\_Tutorial/pyruvate\_in\_water/cgenff\_charmm2gmx.py”, line 1055, in   
main()  
File “/gxfs\_home/cau/sukin806/Projects/GROMACS\_Tutorial/pyruvate\_in\_water/cgenff\_charmm2gmx.py”, line 1030, in main  
params = parse\_charmm\_parameters(prmlines)  
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^  
File “/gxfs\_home/cau/sukin806/Projects/GROMACS\_Tutorial/pyruvate\_in\_water/cgenff\_charmm2gmx.py”, line 274, in parse\_charmm\_parameters  
raise ValueError(  
ValueError: ERROR: Incorrect number of values found in ANGL section  
[sukin806@nesh-login1 pyruvate\_in\_water]$

---

<div class="post-metadata">

**Author:** ![jalemkul](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/jalemkul/32/18_2.png) [@jalemkul](https://gromacs.bioexcel.eu/u/jalemkul)\
**Post date:** [July 30, 2025, 2:03pm UTC](https://gromacs.bioexcel.eu/t/getting-error-when-converting-the-files-using-cgenff-charmm2gmx-py-code/12464/2 "2025-07-30T14:03:06Z")

</div>

This is not a GROMACS question. We are troubleshooting this offline.