# Pdb2gmx: -ter option doesn't work
**URL:** https://gromacs.bioexcel.eu/t/pdb2gmx-ter-option-doesnt-work/12154
**Category:** User discussions
**Tags:** pdb2gmx
**Created:** [May 26, 2025, 1:56pm UTC](https://gromacs.bioexcel.eu/t/pdb2gmx-ter-option-doesnt-work/12154 "2025-05-26T13:56:50Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@AntonBer](https://gromacs.bioexcel.eu/u/AntonBer)
#### Post date: [May 26, 2025, 1:56pm UTC](https://gromacs.bioexcel.eu/t/pdb2gmx-ter-option-doesnt-work/12154/1 "2025-05-26T13:56:50Z")
GROMACS version: 2025.0
GROMACS modification: No
Tried to run pdb2gmx on pdb file from OpenMM+grand simulation to prepare topology file, but got an error:
```auto
gmx pdb2gmx -f 2ZFF_1A_gcmc_3d_npt.pdb -ter
...
Program: gmx pdb2gmx, version 2025.0
Source file: src/gromacs/gmxpreprocess/pdb2gmx.cpp (line 896)
Fatal error:
Atom H1 in residue ACE 1 was not found in rtp entry ACE with 6 atoms
while sorting atoms.
For a hydrogen, this can be a different protonation state, or it
might have had a different number in the PDB file and was rebuilt
(it might for instance have been H3, and we only expected H1 & H2).
Note that hydrogens might have been added to the entry for the N-terminus.
Remove this hydrogen or choose a different protonation state to solve it.
Option -ignh will ignore all hydrogens in the input.
```
I thought `-ter` option will give me choice for protein caps, but not in this case.
How can I solve this issue?
[2ZFF\_1A\_gcmc\_3d\_npt.txt](https://gromacs.bioexcel.eu/uploads/short-url/mIWZEcUqKwjsmF4YcYc2hOsF420.txt) (3.0 MB)
---
### Author:  [@gq0067](https://gromacs.bioexcel.eu/u/gq0067)
#### Post date: [July 16, 2025, 2:14pm UTC](https://gromacs.bioexcel.eu/t/pdb2gmx-ter-option-doesnt-work/12154/2 "2025-07-16T14:14:27Z")
You can give -ignh for this along with ter for H atoms