[gmx-users] problems with energy minimization
mstiebri at biologie.uni-erlangen.de
Mon Aug 28 14:21:48 CEST 2006
I´m a beginner in the field of molecular dynamics and have just installed the
I have problems with energy minimization. When trying out the md tutorial on
the lysozyme structure 1AKI.pdb using the provided minim.mdp file the
minimization finishes with the message:
Stepsize too small, or no change in energy.
Converged to machine precision,
but not to the requested precision Fmax < 1000
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 minim_traj.trr to ./#minim_traj.trr.4#
Back Off! I just backed up confout.gro to ./#confout.gro.4#
Steepest Descents converged to machine precision in 79 steps,
but did not reach the requested Fmax < 1000.
Potential Energy = -1.13948846313191e+04
Maximum force = 1.94715000386709e+03 on atom 1113
Norm of force = 8.53155624640669e+03
I already tried different minimization algorithms with different settings and
also compiled the code with double precision accuracy without success.
Thank you very much for any advice,
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