quadratic constraint question

[Visvaldas Kairys]

I thought I will ask this. I am trying to constrain sulfonamide nitrogen at a certain point in space. After some thinking (and even digging of the code) I put chlorine at the constraint point and use:
-10 atomtypequadratic(t1=Chlorine,t2=NitrogenXSAcceptor,o=0,c=8)
and it seems to work okay.

This seems a bit awkward however. Is there a better way to add "dummy" points? Another problem is I have to strip nitrogen from the hydrogens since the constraint is ignored if there are H attached to N, I decided it must be because of the clash between "dummy" yet "real" Cl and the hydrogen. Basically my question is if I am doing it right.

And, by the way, thank you for awesome software, and I mean it.

[David Koes]

Yes, that is unfortunately the way to do this. Implementing user-friendly constraints (e.g. covalent docking) is on the todo list. You could put rare atom types on both the ligand receptor to make sure the exact atoms you want are interacting.