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On 6/10/2011 11:54 PM, prakash verma wrote:
<blockquote
cite="mid:CAEUanMFi7mSDPAUUOgtqgsX7Uf=JNivzn5waAX7Xp1Wa4acbrw@mail.gmail.com"
type="cite">Dear All,<br>
<br>
while energy minimization with the protein fixed i am getting
following error:<br>
<br>
<br>
<b>t = 0.011 ps: Water molecule starting at atom 21089 can not be
settled.<br>
</b></blockquote>
<br>
Rigid water models and EM are not a great combination. define =
-DFLEXIBLE in the .mdp file is usually a good idea.<br>
Position restraints are normally a better idea than frozen atoms for
EM.<br>
<br>
Mark<br>
<br>
<blockquote
cite="mid:CAEUanMFi7mSDPAUUOgtqgsX7Uf=JNivzn5waAX7Xp1Wa4acbrw@mail.gmail.com"
type="cite"><b>Check for bad contacts and/or reduce the timestep.</b><br>
Even if i am reducing timesteps its not working.<br>
The minim.mdp file which i have used is:; <br>
<br>
<br>
ntegrator = steep ; Algorithm (steep = steepest
descent minimization)<br>
emtol = 1000 ; Stop minimization when the
maximum force < 1000.0 kJ/mol/nm<br>
dt = 0.01<br>
emstep = 0.01 ; Energy step size<br>
nsteps = 20000 ; Maximum number of (minimization)
steps to perform<br>
<br>
constraints = all-bonds ; convert all bond to constraints<br>
; Parameters describing how to find the neighbors of each atom and
how to calculate the interactions<br>
nstlist = 5 ; Frequency to update the neighbor
list and long range forces<br>
ns_type = grid ; Method to determine neighbor
list (simple, grid)<br>
rlist = 1 ; Cut-off for making neighbor list
(short range forces)<br>
coulombtype = PME ; Treatment of long range
electrostatic interactions<br>
rcoulomb = 1 ; Short-range electrostatic
cut-off<br>
rvdw = 1 ; Short-range Van der Waals
cut-off<br>
pbc = xyz ; Periodic Boundary Conditions
(yes/no)<br>
optimize_fft = yes<br>
pme_order = 4<br>
fourierspacing = 0.15<br>
; Non-equilibrium MD stuff<br>
freezegrps = Protein Sol<br>
freezedim = Y Y Y N N N<br>
<br>
<br>
Regards,<br>
Prakash.<br>
<br>
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<br>
</blockquote>
<br>
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