Gmx hbond - contact option

GROMACS version: 2020.6
GROMACS modification: No

Hi everyone.

We want to have a list of all the contacts between two proteins within a 0.5 nm cutoff.

If we want to use the -contact option of gmx hbond we should change the -r flag (0.5 instead of the 0.35 default) and not use the flag -r2, are we right?

In other words, if we are interested in all kind of contacts, leaving -r = 0.35 would be meaningless because this cutoff is specific for h-bonds interaction…

This is what we understood.
we are using this command:

gmx hbond -s .tpr -f .xtc -n .ndx -g hbond_ref.log -hbn hbindex_ref.ndx -contact -r 0.5

any comment would be helpful.
thank you!

The better approach to counting generic contacts is gmx mindist -on.