My simulation set up is as follows:
I have a fluid layer sandwiched between an upper and lower surface . My surface is modelled by a pairwise interaction (modified Buckingham) where the surface atoms have partial charges. Electrostatics are calculated using the USER-EWALD-N routine. I am looking do perform shear simulations where I simply assign a fixed velocity to the atoms in the upper and/or lower surface. My boundary conditions are periodic in the x&y direction and non-periodic fixed in z direction.
I am wondering whether it is possible to turn off the calculations of forces on the surface atoms with each other, including electrostatics. I am not interested in the dynamics or vibrations of the surface atoms. After I assign initial velocities to the surface atoms (e.g to shear in the x or y direction) I want the surface slab structure to remain 'fixed'. i.e just the initial surface slab configuration moving with a fixed velocity in a particular direction.
I would still want have the pairwise interaction of fluid/fluid, fluid/surface, and the electrostatics of fluid/fluid, fluid/surface.
I am hoping if I can turn off these surface/surface calculations I can speed up my simulations, as it I will not be spending a significant amount of time calculating the forces/ vibrations of surface atoms with each other, which is not important to the simulations that I am trying to do.
Sorry for the long question, but I was wanting to make it as clear as possible.