AMBER Archive (2002)

Subject: Re: Minimization in GB-SA-E-Spikes, LINMIN

From: Sarangan Ravichandran (sravi_at_ncifcrf.gov)
Date: Tue Jul 16 2002 - 12:11:27 CDT


Hi Andreas:

Thanks for your reply.
I will try that, but, I have
seen this even with sander_classic in
AMBER6.

Thanks
Ravi
Andreas Svrcek-Seiler wrote:
>
> Hi,
> > During minimization,
> > I keep seeing energy spikes at regular
> > intervals (ex 100 steps in some cases) after
> > few 1000 steps. My starting configuration has
> > no bumps and the energy is close to zero.
> > I also have the LINMIN FAILURE message during
> > minimization. I am aware of the web-page in amber
> > home which discusses LINMIN issues. My question is
> > how to handle the energy spikes and LINMIN failures.
> ...I *believe* the SA contribution to the total energy
> is not everywhere differentiable, therefore possibly confusing
> the minimization routine.
> I'd try to do the minimization without 'gbsa'
> and calculate the non-polar solvation part afterwards,
> I bet it won't make much difference.
>
> Best regards
> Andreas
> --
>
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> (((((
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> o Wolfgang Andreas Svrcek-Seiler
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