Hello. What is the difference between fix move and fix aveforce? In my simulation, I have a graphene sheet that I want to control the pressure on both sides of the membrane by moving it and bring it to a certain point depending on the pressure. Can I do it by using fix move? or i must do it by fix aveforce? Meanwhile, I applied the fix Langevin for the membrane and the graphene sheet
thanks
With fix move atoms follow a pre-described motion and they will ignore their forces.
Fix aveforce averages the total force on a group of atoms and redistributes it; in the process and additional force may be added. Fix move includes time integration, fix aveforce doesn’t.
From your description, it should be possible to apply either. Making this dependent on pressure is going to be a tricky thing, since computing the pressure for subsystems is not well defined. It would be more straightforward to determine which net force should be created by the sheet and then use fix addforce or fix aveforce to apply it.