Pressurized water filteration

LAMMPS LAMMPS General Discussion
1

Hi,

I am studying water and ion permeation through a polyoxometalate membrane. The model uses a graphene wall as a piston to push the water through the polyoxometalate membrane. The charge on the piston wall is set to zero to avoid electrostatic interactions, and the Vander Waals interactions are modeled using LJ Potential. The piston can push the water without any challenge at a very high-pressure value (around a thousand bars which is more than what people generally use). When I use pressure in hundreds of bars (what generally people are using), the LJ interactions between water and polyoxometalate are so strong that instead of pushing the water, some water molecules are attracted towards the Piston, and some are attracted towards the membrane creating a partial vacuum in between.

Any help would be much appreciated.

membrane
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2

You should change the forum category of your post to something else than LAMMPS, perhaps ScienceTalk. Your post is off-topic for this one.

This is not a LAMMPS issue but a question about how to do your research. That makes it first and foremost a topic for a discussion with the people that are advising/mentoring/tutoring you about how to do your research and how to set up these simulations. LAMMPS simply does what you are asking it to do through defining your model and input parameters. It does not care whether it is meaningful. It just executes the programmed algorithms.

3

Thanks. You are right.