[lammps-users] oscillations in desired values of temperature and pressure


My system is a very small collection of 5 of solvated polymer chains.

While using NVT/NPT fix, when i try to run it for first 500-1000 steps, the
temperature(i want near 300 K) and pressure(i want near 5-10 atm) oscillate
wildly in the later stage.

My initial velocities could be zero or scaled to 300 K temperature.

I tried changing
1.Tstart and Tstop
2.Pstart and Pstop
3.Damping parameter
4.Drag value

and once i got okay stuff for a particular combination, but i would like to have
a word of advice if possible on above 4 factors

Also at the end of the run it seems to cross no of steps once or twice i get a
***glibc detected***double free or corruption(out):ox09...Aborted

Could it be because of wild oscillations of pressure or temperature?
Thanks in advance

Pressures oscillate and they oscillate more
for small systems. Try the drag parameters of
fix nvt and fix npt if you are asking it to equlibrate
far from where you start.