Hi everyone,
Forces does not converge. The bonds also distort in the final frame/ long distance.
GROMACS version: 2024.4
GROMACS modification: Yes
Energy minimization has stopped, but the forces have not converged to the
requested precision Fmax < 500 (which may not be possible for your system).
It stopped because the algorithm tried to make a new step whose size was too
small, or there was no change in the energy since last step. Either way, we
regard the minimization as converged to within the available machine
precision, given your starting configuration and EM parameters.
Double precision normally gives you higher accuracy, but this is often not
needed for preparing to run molecular dynamics.
You might need to increase your constraint accuracy, or turn
off constraints altogether (set constraints = none in mdp file)
writing lowest energy coordinates.
Back Off! I just backed up em.gro to ./#em.gro.1#
Steepest Descents converged to machine precision in 2062 steps,
but did not reach the requested Fmax < 500.
Potential Energy = -5.0807432e+07
Maximum force = 1.5580516e+04 on atom 169932
Norm of force = 2.1943692e+01
mdp file:
integrator = steep
emtol = 500.0
nsteps = 100000
nstlist = 10
cutoff-scheme = Verlet
rlist = 1.2
vdwtype = Cut-off
vdw-modifier = Force-switch
rvdw_switch = 1.0
rvdw = 1.2
coulombtype = PME
rcoulomb = 1.2
;
constraints = h-bonds
constraint_algorithm = LINCS
Can I remove the constraints to avoid this error?
Thanking you
Manisha