Re: AMBER: extracting starting structures from equilibration trajectory

From: Carlos Simmerling <carlos.simmerling.gmail.com>
Date: Thu, 7 Jun 2007 15:41:36 -0400

yes- page 91 of the amber9 manual. set ntwr to a negative value.


On 6/7/07, Nikola Trbovic <nt2146.columbia.edu> wrote:
>
> Thanks for the quick reply!
>
> Is there perhaps a way to save .rst files at regular intervals during the
> equilibration run in a way that they are not overwritten?
>
> -----Original Message-----
> From: owner-amber.scripps.edu [mailto:owner-amber.scripps.edu] On Behalf
> Of
> Ilyas Yildirim
> Sent: Thursday, June 07, 2007 2:14 PM
> To: amber.scripps.edu
> Subject: Re: AMBER: extracting starting structures from equilibration
> trajectory
>
> The .mdcrd files do not store any velocity information. So, when u extract
> the restart files from a .mdcrd file using ptraj, they wont have any
> velocity information in them. As a result, u need to re-equilibrate each
> system. Only .rst files have velocity info. in them.
>
> On Thu, 7 Jun 2007, Nikola Trbovic wrote:
>
> > Dear all,
> >
> >
> >
> > I'm trying to use snapshots from an NPT equilibration trajectory as
> starting
> > structures for several NVE production runs. I tried extracting snapshots
> as
> > Amber restart files from the equilibration trajectory as follows:
> >
> >
> >
> > ptraj prmtop << EOF
> >
> > trajin equi.mdcrd 300 1000 100
> >
> > trajout start restart
> >
> > EOF
> >
> >
> >
> > This produces 8 restart files from the equilibration trajectory, just
> like
> I
> > want it to. But when I start the production runs with irest=1 and ntx=5,
> the
> > temperature starts out around 190K, although it is clearly equilibrated
> at
> > 300K in the time window of the NPT equilibration trajectory that I
> specified
> > for extracting the starting structures by ptraj. How do I fix this?
> >
> >
> >
> > Thanks a lot in advance for any suggestions,
> >
> > Nikola
> >
> >
>
> --
> Ilyas Yildirim
> ---------------------------------------------------------------
> - Department of Chemistry - -
> - University of Rochester - -
> - Hutchison Hall, # B10 - -
> - Rochester, NY 14627-0216 - Ph.:(585) 275 67 66 (Office) -
> - http://www.pas.rochester.edu/~yildirim/ -
> ---------------------------------------------------------------
>
> -----------------------------------------------------------------------
> The AMBER Mail Reflector
> To post, send mail to amber.scripps.edu
> To unsubscribe, send "unsubscribe amber" to majordomo.scripps.edu
>
> -----------------------------------------------------------------------
> The AMBER Mail Reflector
> To post, send mail to amber.scripps.edu
> To unsubscribe, send "unsubscribe amber" to majordomo.scripps.edu
>

-----------------------------------------------------------------------
The AMBER Mail Reflector
To post, send mail to amber.scripps.edu
To unsubscribe, send "unsubscribe amber" to majordomo.scripps.edu
Received on Sun Jun 10 2007 - 06:07:28 PDT
Custom Search