Re: [AMBER] Large Energy Jump in TMD simulation - Regarding

From: Carlos Simmerling <carlos.simmerling.gmail.com>
Date: Fri, 30 Mar 2012 09:41:13 -0400

can you just paste the sander input to an email as text?


On Fri, Mar 30, 2012 at 9:34 AM, Fredrick Devadoss <
Fredrick.Devadoss.uni-konstanz.de> wrote:

> Dear Carlos and other AMBER users/developers,
>
> The simulations were done with AMBER 10 and you can find the input files
> in the following link:
>
> http://www.tcd.uni-konstanz.de/AMBER_MAIL/amber.tar
>
> Expecting your replies and thanks in advance.
>
> Warm regards
> Fredrick.
>
>
>
> On Friday, March 30, 2012 14:52 CEST, Carlos Simmerling <
> carlos.simmerling.gmail.com> wrote:
>
> > Please include your input file so we can see what you are trying to do.
> > Also tell us the amber version.
> > On Mar 30, 2012 8:20 AM, "Fredrick Devadoss" <
> > Fredrick.Devadoss.uni-konstanz.de> wrote:
> >
> > > Dear AMBER users and developers:
> > >
> > > We run into a problem with targeted MD and we have absolutely no clue
> what
> > > causes them. We first run 10ns of normal MD simulations on the system
> > > without any problem. Then we started the targeted MD. After a few
> steps, we
> > > see a large jump of more than 50000 kcal/mole in the total energy (see
> > > attached file and summary below). We analyzed this behavior in detail
> and
> > > the change is due to extremely more favorable electrostatic
> interactions of
> > > the solvents molecules. But by visual inspection, no large difference
> can
> > > be seen. The simulation box has the same size (another behavior would
> have
> > > been very surprising since we did a NVT simulation but you never know)
> and
> > > also the protein does not change much (all-atom rmsd difference before
> and
> > > after the energy jump of 1 .4 Angstrom). Also some other simulations
> on the
> > > same system but with other restraint mask show the same behavior even
> if
> > > the energy jumps sometimes start much later in the simulation. Does
> anybody
> > > has an idea what can be
> > > going wrong here.
> > >
> > > The system is a DNA-protein complex and we are happy to share the
> input as
> > > well as the output. But due to size limitations, we cannot attach them
> > > directly to this email. Thus, we would put them on our web server on
> demand.
> > >
> > >
> > >
> ===============================================================================
> > >
> > > A V E R A G E S O V E R 500000 S T E P S
> > >
> > >
> > > NSTEP = 500000 TIME(PS) = 12700.000 TEMP(K) = 302.76 PRESS =
> > > 0.0
> > > Etot = -243182.8774 EKtot = 43990.9686 EPtot =
> > > -287173.8460
> > > BOND = 711.6154 ANGLE = 2039.5414 DIHED =
> > > 5355.1836
> > > 1-4 NB = 1906.4843 1-4 EEL = 11768.4366 VDWAALS =
> > > 38849.0992
> > > EELEC = -347819.8167 EHBOND = 0.0000 RESTRAINT =
> > > 15.6103
> > > EAMBER (non-restraint) = -287189.4563
> > > Ewald error estimate: 0.7088E-04
> > > Current RMSD from reference: 3.193
> > > Current target RMSD: 3.000
> > >
> > >
> ------------------------------------------------------------------------------
> > >
> > > NMR restraints: Bond = 0.000 Angle = 0.000 Torsion =
> 0.000
> > >
> > >
> ===============================================================================
> > >
> > > R M S F L U C T U A T I O N S
> > >
> > >
> > > NSTEP = 500000 TIME(PS) = 12700.000 TEMP(K) = 1.73 PRESS =
> > > 0.0
> > > Etot = 14406.0444 EKtot = 252.0661 EPtot =
> > > 14630.3082
> > > BOND = 369.4600 ANGLE = 885.9235 DIHED =
> > > 234.8907
> > > 1-4 NB = 75.4107 1-4 EEL = 32.6070 VDWAALS =
> > > 2705.6396
> > > EELEC = 15698.4882 EHBOND = 0.0000 RESTRAINT =
> > > 14.8110
> > > EAMBER (non-restraint) = 14615.4972
> > > Ewald error estimate: 0.3253E-04
> > > Current RMSD from reference: 3.193
> > > Current target RMSD: 3.000
> > >
> > >
> ------------------------------------------------------------------------------
> > >
> > >
> > > Your replies are highly appreciated.
> > >
> > >
> > > Warm regards
> > > Fredrick Robin Devadoss V.
> > > Ph.D. Student
> > > Dr. Thomas Exner Group
> > > University of Konstanz
> > > Konstanz, Germany.
> > >
> > > _______________________________________________
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> > > AMBER.ambermd.org
> > > http://lists.ambermd.org/mailman/listinfo/amber
> > >
> > >
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>
>
>
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Received on Fri Mar 30 2012 - 07:00:05 PDT
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