Hydrogen bond angle cutoff criteria

[Srijan Chatterjee]

Hi everyone!

I was reading through hydrogen bond analysis section , and could find option for  d_h_a_angle_cutoff.

Would there be an option, so that I can use the h_d_a_angle cutoff instead? 

If anyone could comment a bit on this, I would be grateful.
Best regards
--
Srijan 

[Oliver Beckstein]

Hi Srijan,

Can you explain what you want to achieve with a "h_d_a_angle cutoff" setting?

There's no alternative kwarg to d_h_a_angle_cutoff  in https://docs.mdanalysis.org/dev/documentation_pages/analysis/hydrogenbonds.html#MDAnalysis.analysis.hydrogenbonds.hbond_analysis.HydrogenBondAnalysis : we always consider the D-H-A angle (i.e., the hydrogen H forms the apex of the angle and 180º is fully extended or straight). If you want to use a different angle, then you have to use trigonometry to calculate the transformation between your preferred angle definition and the D-H-A that is used here.

Best,

Oliver