Hi all, 

I am working on the capillary transport of NaCl solution through CSH nanopore. Most of the related MD studies were performed through LAMMPS as shown in the first figure.

I'm just wondering if it is possible to do this in Materials Studio? 

I've built a similar model using MS (as shown in second figure). The next step is i will need to apply a constant force on the solution at specified direction. To achieve that, I've wrote a perl script to exert external force on the solution set, running in forcite dynamics. However, if I don't keep the CSH walls in constraint, they'll move away from its position drastically before be in contact with the solution. 

Is there a way to only apply force on the solution set while letting the rest of the system remains stationary before they're interacting with the solution?
Or am I making any mistakes in my simulation? Can anyone pls shed light on this? Thanks