# Overcoming fatal errors in Gromacs

**URL:** https://gromacs.bioexcel.eu/t/overcoming-fatal-errors-in-gromacs/7360
**Category:** User discussions
**Created:** [October 10, 2023, 5:52am UTC](https://gromacs.bioexcel.eu/t/overcoming-fatal-errors-in-gromacs/7360 "2023-10-10T05:52:54Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![rspavan61](https://avatars.discourse-cdn.com/v4/letter/r/85e7bf/32.png) [@rspavan61](https://gromacs.bioexcel.eu/u/rspavan61)
#### Post date: [October 10, 2023, 5:52am UTC](https://gromacs.bioexcel.eu/t/overcoming-fatal-errors-in-gromacs/7360/1 "2023-10-10T05:52:54Z")

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GROMACS version: 2021.4-2  
GROMACS modification: No  
Here post your question

I ran the command for protein topology ’ gmx pdb2gmx -f modified.pdb -o protein\_processed.gro -ter ’ by the use of CHARMM all-atom force field and selected 5ter and 3ter as terminus types and getting the error

Fatal error:  
Atom C7 in residue DT 1 was not found in rtp entry DT with 30 atoms  
while sorting atoms.

how to overcome this ?