simulating water using fix shake

Dear users,

The LAMMPS version is 7 Dec 2015.

I simulate water by using fix shake command, after this, I cut my water into desire shape and merge them with pyrophyllite. However, when I begin the simulation, step 0 shows that the pressure is nan and crush. I attached my water simulation input script(in.water) and also the water-pyrophyllite simulation input data(in.wet). When I close fix shake command in both water simulation and water-pyrophyllite simulation, there is no problem happening. Does anyone have any idea about this?
Thank you.

Miao-Chun

in.water (1.06 KB)

in.wet (1.39 KB)