[lammps-users] "Lost atom" error in high ion concentrations

Hi
I simulate the electro-osmotic flow (EOF) by LAMMPS.

first, create saltwater 1 molar(NaCl) and add sodium ion and all system charge neutralization with an additional charge on the channel atoms uniformly.

In all cases, the system equilibrates for 2 ns, after that at 0.025 volts/Angstrom electric field run10 ns to ensure that a steady-state reach and then an additional 30 ns execute for collecting data and statistical averaging.

in my simulation:
all pair style is Lj/Charmm/Coul/long 8 11
time step 1fs
water model is SPC/E
update neighborhood list every timestep without delay

We have not any problems when Na+ ions are low concentration. The problem makes cause when we have more than 60 of Na+ ions in solution. In the latter case “lost atom” is observed.

changing timestep, increasing simulation box length were not removed the error.

thanks

Kazem Phd. student of physic
K. N. Toosi University of Technology

There is not enough information here to give any specific advice.

You should visualize the failing simulations to see which atoms are moving too fast.