Dear LAMMPS users,
I am having trouble achieving equilibrium when running a small simulation (192 atoms) on Li4Ti5O12. I am using the nvt command and running the simulation for several nanoseconds but the temperature continues to fluctuates between 220 and 400 without ever achieving the required 300 K.
I believe this issue has to do with the relaxation time. I read that it is typically recommended that the relaxation time be about 100 timesteps but I have also tried other values to no avail.
Does anyone have any ideas as to what may be happening here?
Additionally, I am trying to calculate msd for Lithium. I am following the instructions in the manual but my results don’t make any sense. I am using the “compute msd” command and plotting “time vs the 4th column of output”.
I think this may be related to the fact that I cannot currently achieve equilibrium.
I have attached my input file to this message. Any help would be greatly appreciated.
in.solid (1.07 KB)
in.data.txt (8.07 KB)
Dear LAMMPS users,
I am having trouble achieving equilibrium when running a small simulation (192 atoms) on Li4Ti5O12. I am using the nvt command and running the simulation for several nanoseconds but the temperature continues to fluctuates between 220 and 400 without ever achieving the required 300 K.
I believe this issue has to do with the relaxation time. I read that it is typically recommended that the relaxation time be about 100 timesteps but I have also tried other values to no avail.
Does anyone have any ideas as to what may be happening here?
Additionally, I am trying to calculate msd for Lithium. I am following the instructions in the manual but my results don’t make any sense. I am using the “compute msd” command and plotting “time vs the 4th column of output”.
I think this may be related to the fact that I cannot currently achieve equilibrium.
I have attached my input file to this message. Any help would be greatly appreciated.
in.solid (1.07 KB)
in.data.txt (8.07 KB)
Dear LAMMPS users,
I am having trouble achieving equilibrium when running a small simulation (192 atoms) on Li4Ti5O12. I am using the nvt command and running the simulation for several nanoseconds but the temperature continues to fluctuates between 220 and 400 without ever achieving the required 300 K.
I believe this issue has to do with the relaxation time. I read that it is typically recommended that the relaxation time be about 100 timesteps but I have also tried other values to no avail.
Does anyone have any ideas as to what may be happening here?
Additionally, I am trying to calculate msd for Lithium. I am following the instructions in the manual but my results don’t make any sense. I am using the “compute msd” command and plotting “time vs the 4th column of output”.
I think this may be related to the fact that I cannot currently achieve equilibrium.
I have attached my input file to this message. Any help would be greatly appreciated.
in.solid (1.07 KB)
in.data.txt (8.07 KB)
Dear LAMMPS users,
I am having trouble achieving equilibrium when running a small simulation
(192 atoms) on Li4Ti5O12. I am using the nvt command and running the
simulation for several nanoseconds but the temperature continues to
fluctuates between 220 and 400 without ever achieving the required 300 K.
I believe this issue has to do with the relaxation time. I read that it is
typically recommended that the relaxation time be about 100 timesteps but I
have also tried other values to no avail.
this sounds like you need to have a good chat with your adviser about
ensemble averages, strategies to reach equilibrium, and for MD of
soilds in general.
temperature (or kinetic energy) for small systems fluctuates (consider
the smallest system: a harmonic oscillator) and even more so for
solids because their internal force constants are larger.
this is all text book stuff. so please start looking there.
axel.