Re: [AMBER] Using cpptraj to trim a range of water residues while maintaining a periodic box

From: Joe Passman <joepassman.comcast.net>
Date: Tue, 12 Feb 2013 04:51:44 +0000 (UTC)

Thank you. I am going to increment my box length in leap as the radius of gyration of my systems decrease. Thank you for mentioning vacuum pockets. This will save time during equilibration. I also appreciated the script ideas.


Thanks!


Joe Passman


----- Original Message -----
From: "Daniel Roe" <daniel.r.roe.gmail.com>
To: "AMBER Mailing List" <amber.ambermd.org>
Sent: Sunday, February 10, 2013 7:58:03 PM
Subject: Re: [AMBER] Using cpptraj to trim a range of water residues while maintaining a periodic box

Hi,

You can strip atoms and generate a corresponding prmtop with cpptraj
in one step. Also, if you specify 'nobox' you're getting rid of box
information (which it sounds like you want to keep) from your
coordinates, so I would remove that keyword. For example:

parm prmtop
trajin wb_lambdaN_100.crd
strip :WAT&!(:50000-155000) outprefix strip
trajout wb_strip_lambdaN_100.crd

will strip the desired atoms, write out a stripped trajectory
(wb_strip_lambdaN_100.crd) and write out the corresponding topology
(strip.prmtop). You can do the same thing with the 'closest' command:

parm prmtop
trajin wb_lambdaN_100.crd
closest 105000 <solute mask> outprefix closest
trajout wb_closest_lambdaN_100.crd

will retain the closest 105000 solvent molcules to your solute mask,
writing out the corresponding topology as closest.prmtop.

As Jason said, if you do decide to strip your systems in this way you
need to equilibrate them very carefully, especially when using the
'strip' command as you may end up with pockets of vacuum in your
solvent.

Hope this helps,

-Dan

-- 
------------------------- 
Daniel R. Roe, PhD 
Department of Medicinal Chemistry 
University of Utah 
30 South 2000 East, Room 201 
Salt Lake City, UT 84112-5820 
http://home.chpc.utah.edu/~cheatham/ 
(801) 587-9652 
(801) 585-9119 (Fax) 
_______________________________________________ 
AMBER mailing list 
AMBER.ambermd.org 
http://lists.ambermd.org/mailman/listinfo/amber 
_______________________________________________
AMBER mailing list
AMBER.ambermd.org
http://lists.ambermd.org/mailman/listinfo/amber
Received on Mon Feb 11 2013 - 21:00:02 PST
Custom Search