# Gmx-hbond: No donors No acceptors

**URL:** <https://gromacs.bioexcel.eu/t/gmx-hbond-no-donors-no-acceptors/10319>\
**Category:** User discussions\
**Created:** [October 10, 2024, 10:15pm UTC](https://gromacs.bioexcel.eu/t/gmx-hbond-no-donors-no-acceptors/10319 "2024-10-10T22:15:02Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Alex\_Beer](https://avatars.discourse-cdn.com/v4/letter/a/ce7236/32.png) [@Alex\_Beer](https://gromacs.bioexcel.eu/u/Alex_Beer)\
**Post date:** [October 10, 2024, 10:15pm UTC](https://gromacs.bioexcel.eu/t/gmx-hbond-no-donors-no-acceptors/10319/1 "2024-10-10T22:15:02Z")

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GROMACS version: 2024.2-dev  
[apt1\_OL21\_solv-neu\_GMX.top](https://gromacs.bioexcel.eu/uploads/short-url/zBhfm41e9gizxFPyYH4H9df2Z8d.top) (2.0 MB)

GROMACS modification: Yes/No  
Hi,  
I can’t understand why gmx-hbond return the error:

```auto
Checking for overlap in atoms between DNA (2709 atoms) and DNA (2709 atoms)
WARNING: Selection 'DNA' has no acceptors!
WARNING: Selection 'DNA' has no donors!

```

While hbond-legacy gives no problem; don’t know if relevant but for the same system if I use OPC instead of TIP3P the command works properly.

I’ve attached topology file: I’m still using tleap to build the system with ff OL21.

Any suggestions?

Best regards

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<div class="post-metadata">

**Author:** ![ximi](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/ximi/32/3715_2.png) [@ximi](https://gromacs.bioexcel.eu/u/ximi)\
**Post date:** [October 16, 2024, 6:08am UTC](https://gromacs.bioexcel.eu/t/gmx-hbond-no-donors-no-acceptors/10319/2 "2024-10-16T06:08:19Z")

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I came across the same issue too. But tried a few times later, I noticed it would work well if I change the tpr file. Initially I used a gro file for -s flag input. The program could run, but complained for no acceptors no donors. Changing the tpr file to another file could work for me.