[gmx-users] Different nstxout and nstvout in mdp file gives totally different trajectory

[Tanping Li]

Dear all,

I run a 1ns trajectory for a protein in water. by
accidence, I find that the minor different in mdp file
gives two totally different trajectories. By setting 

nstxou=500
nstvou=500;

and 

nstxou=2500
nstvou=2500;

There is very large difference between two
trajectories (dt=2fs in both cases). I am really
confused: nstxou JUST sets the frequency to output the
coordinate, why I get different results? Looking
forward to your opinion and thanks a lot.

Yours
Tanping Li