The simulation box expands crazily

Hello everyone
    I try to simulate the water with NaCl.
    The structure had been minimized. Then I tried to run in NPT ensemble. But the atom didn't move and the box expand. The final volume is 1343100.89906575 with the initial value 208000.
    Any suggestion will be appreciate.
Best

log.lammps (6.71 KB)

pair_coeff.txt (1.27 KB)

in.lammps (1.25 KB)

your interactions parameters seems very complex... and then might
contains error/typos: just one wrong coeff and your system will blowup!

Before running an NPT, did check whether you get ground state properties
correctly, like the cohesive energy?

Also, before the NPT, it is usually good to equilibrate your system in
the NVE ensemble.
Give velocities equivalent to 600K.
Run NVE --> you should get a stable trajectories around 300K. If not,
your initial system is probably wrong.

Julien