Dear All,
I want to model a lubricant between two Aluminium solid surfaces. Therefore, I used 3 different regions and assigned 3 different groups to each region.
For fixing the two above and bottom Al surfaces, I used the following command:
fix freezetop AlumTop setforce 0.0 0.0 0.0
fix freezebot AlumBot setforce 0.0 0.0 0.0
But after a few steps of NVT run, these two surfaces have disintegrated and I think it is due to fixing setforce command.
Is there any other way to fix these surfaces to make them not move along the z direction?