[gmx-users] Water molecule starting at atom X can not be settled.

[sreelakshmi ramesh]

Dear gmx-users,
                           I have a problem during minimization  and shows a
error that water molecules starting at atom X cannot be settled  i had
attached the output of mdrun below. I read the earlier post for same problem
faced by other gmx users.tried to reduce the timestep still facing the same
error.Tried diff water model and force fields as well to check if i get the
same error .But still irrespective of any water model and forcefield i get
the same  error.And  was not able to find a solution.Any suggestion
please....

*
OUTPUT OF MDRUN*

Back Off! I just backed up md.log to ./#md.log.1#
Reading file em.tpr, VERSION 4.5.3 (single precision)
Starting 2 threads
Making 1D domain decomposition 2 x 1 x 1

Back Off! I just backed up em.trr to ./#em.trr.1#

Back Off! I just backed up em.edr to ./#em.edr.1#

Steepest Descents:
   Tolerance (Fmax)   =  1.00000e+02
   Number of steps    =       200000

step 7: Water molecule starting at atom 7619 can not be settled.
Check for bad contacts and/or reduce the timestep if appropriate.

step 7: Water molecule starting at atom 3547 can not be settled.
Check for bad contacts and/or reduce the timestep if appropriate.
Wrote pdb files with previous and current coordinates
Wrote pdb files with previous and current coordinates

step 12: Water molecule starting at atom 7619 can not be settled.
Check for bad contacts and/or reduce the timestep if appropriate.
Wrote pdb files with previous and current coordinates

step 17: Water molecule starting at atom 8007 can not be settled.
Check for bad contacts and/or reduce the timestep if appropriate.
Wrote pdb files with previous and current coordinates

step 22: Water molecule starting at atom 8511 can not be settled.
Check for bad contacts and/or reduce the timestep if appropriate.
Wrote pdb files with previous and current coordinates

Stepsize too small, or no change in energy.
Converged to machine precision,
but not to the requested precision Fmax < 100

Double precision normally gives you higher accuracy.
You might need to increase your constraint accuracy, or turn
off constraints alltogether (set constraints = none in mdp file)

writing lowest energy coordinates.

Back Off! I just backed up confout.gro to ./#confout.gro.1#

Steepest Descents converged to machine precision in 40 steps,
but did not reach the requested Fmax < 100.
Potential Energy  =  2.4059008e+07
Maximum force     =  2.8605226e+08 on atom 8511
Norm of force     =  3.7174682e+06

gcq#324: "Your Country Raised You, Your Country Fed You, and Just Like Any
Other Country it Will Break You" (Gogol Bordello)
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