VMD-L Mailing List

From: Josh Vermaas (vermaas2_at_illinois.edu)
Date: Thu Apr 25 2013 - 14:51:15 CDT

Hi Salomon,

The most coding-time efficient way of doing this is probably to write
out all the hbond lists using "measure hbonds", and then parse the
result based on name or type.

Something like:

set all [atomselect top all]
set superlist [list [measure hbonds 3.0 30 $all]]
set donorindices [lindex $superlist 0]
set acceptorindices [lindex $superlist 1]
set hydrogenindices [lindex $superlist 2]
set typelist [$all get type]
for { set i 0 } { $i < [llength $donorindices] } { incr i } {
    puts "[lindex $typelist [lindex $donorindices $i]] [lindex $typelist
[lindex $hydrogenindices $i]] [lindex $typelist [lindex $acceptorindices
$i]] "
}

Is that what you had in mind?

-Josh Vermaas

On 04/25/2013 01:13 PM, Salomon Turgman Cohen wrote:
> Hello,
>
> I have the need to detect hydrogen bond like interactions in a system
> consisting of amines and some ions. I was thinking the best way to do
> this is to use the salt-bridges or h-bonds extension but I cannot
> quite understand how to adapt them to my system.
>
> What I would like to do is define a set of donors, hydrogen, and
> acceptors according to their types. So I will give the program
> something like this:
>
> hbonds=((NH3,H3,OO),(NH2,H2,OO),(NH1,H1,OO),...)
>
> In this manner I will tell VMD to look for the those interactions
> according to specific distance and angular cutoffs. What would be the
> best way to implement something like this? Should I work from the
> current hbond plugin and generate my own, or would it be better to
> write a script from scratch? Could I use python scripting? Or would I
> need the TCL functionality in this case?
>
> Salomon
>
> --
> Salomon Turgman Cohen
> Postdoctoral Associate
> Cornell University
> (919) 341-9650