AMBER Archive (2000)

Subject: shake/potential function

From: Andrew Aird (a.aird_at_physik.uni-stuttgart.de)
Date: Thu Nov 02 2000 - 10:08:23 CST

Hi all ... again :-)

I'm trying to simulate a very large molecule. For this reason I'm doing a
vacuum simulation and I use shake on all bonds (ntc = 3 with ntf = 3) in order
to save as much computational time as possible. (Larger timestep...) But I get
the following message:

     COORDINATE RESETTING CANNOT BE ACCOMPLISHED,
     DEVIATION IS TOO LARGE
     NITER, NIT, LL, I AND J ARE : 0 11 4973 3178 3180

What does this mean?

Perhaps I didn't use the correct input file, so here it is:

MD test-run: no PME, no GB, 10ps, no periodicity, shake on all bonds, 1fs
timestep
 &cntrl
  igb = 3, ntb = 0, ntpr = 50, ntwx = 50,
  cut = 9.0, nmropt = 1, ntc = 3, ntf = 3,
  tempi = 0.0, temp0 = 300.0, ntt = 1, tautp = 0.5,
  imin = 0,
  nstlim = 10000, dt = 0.001,
 &end
 &wt
 type='TEMP0', istep1=0, istep2=2000,
 value1=0.0, value2=50.0,
 &end
 &wt
 type='TEMP0', istep1=2001, istep2=5000
 value1=50.0, value2=300.0,
 &end
 &wt
 type='TEMP0', istep1=5001, istep2=10000
 value1=300.0, value2=300.0,
 &end
 &wt
 type = END,
 &end
 &rst
 iat = 0,
 &end
END

Thanks a lot in advance...

Andrew
---------------------------------------------------
Andrew Aird
3.Physikalisches Institut
Universität Stuttgart
Pfaffenwaldring 57
D 70184 Stuttgart
e-mail: a.aird_at_physik.uni-stuttgart.de
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