Hi everybody
my system is a box 50*50*50(A) in real units , with timestep 1 fs ,
force field is opls/AA , I want volume in output , how can I figured
out that my system get to equilibrium? when I plot
potential vs. step my system get to equilibrium in 1 ns , but MSD that
I command that this way :
variable msdtot equal "c_msd[4]"
compute msd all msd com yes
fix msd all ave/time 1 1 100 c_msd[4] file msddumpfile
don't get to equilibrium till 11 ns !!!
what's wrong with my command or simulation?
I use the 3rd way to approximate that system get to equilibrium that
this way has very fluctuation and till 11 ns don't get to equilibrium
, this way is compare average of volume of 20 to last data with
average of 20 to previous data of volume and when that tend to zero
explain that system get to equilibrium ,Is that true? ,
please guide me
thanks
Your Q isn’t very clear. What do you mean by MSD not in
equilibrium? The MSD should continually increase in a diffusing
system and become linear. If it’s noisy it may simply mean
you need better statistics, not that you aren’t in equilibrium.
Steve