[gmx-users] poor minimization?

[Chetan Mahajan]

Hi

I am simulating a system consisting of TiO2 crystal (2160 atoms position
restrained), 3656 water molecules, 1 formate and 1 sodium ion. All of my
energy minimizations (5000 steps or more) are getting over in few seconds
(both for steepest descent as well as conjugate gradient). Would you call
that a poor minimization with following data to add more information? If
yes, what could be done to improve it?

(Also note very high value of the maximum force in all trials)

Steepest Descents did not converge to Fmax < 10 in 5001 steps.
Potential Energy  = -1.8874660e+06
Maximum force     =  9.7974286e+02 on atom 2161
Norm of force     =  1.2869212e+01

Steepest Descents did not converge to Fmax < 10 in 5001 steps.
Potential Energy  = -1.8869792e+06
Maximum force     =  2.2741604e+03 on atom 2161
Norm of force     =  2.5534626e+01

Polak-Ribiere Conjugate Gradients:
   Tolerance (Fmax)   =  1.00000e+01
   Number of steps    =        10000
   F-max             =  6.04871e+03 on atom 563
   F-Norm            =  8.55788e+02

Thanks
Chetan