Dear lammps users,
For the study of the interaction between two thin films that are located very close to each other, how can I avoid coalescence-like behavior (merging) of thin films? Is fix-momentum a good choice? Should I set all three momentum components to 1?
fix 1 thinfilm1 momentum 10 linear 1 1 1
fix 2 thinfilm2 momentum 10 linear 1 1 1
Dear lammps users,
For the study of the interaction between two thin films that are located very close to each other, how can I avoid coalescence-like behavior (merging) of thin films? Is fix-momentum a good choice? Should I set all three momentum components to 1?
no. whether the films will merge depends on the physics, i.e. the interactions defined in the potential functions, particularly the pair potential.
if the physics of the model is not such that the films stay separate but merge, what meaning would any study have that forces them apart?
axel.
Thanks, Axel,
The “only” reason for fixing COM momentum is to measure total interaction energy. I know it is unrealistic, but I guess this way is the only way to accurately measure the interaction energy.
Thanks, Axel,
The “only” reason for fixing COM momentum is to measure total interaction energy. I know it is unrealistic, but I guess this way is the only way to accurately measure the interaction energy.
again, you cannot “cheat” physics. it is definitely possible to determine the “interaction energy” between such two films - even when they are merging - by defining them as groups - and use compute group/group. but it is not clear what you consider a relevant “total interaction energy”. my suspicion is that you are trying to apply concepts that are valid for studying macroscopic objects to the atomic scale and that does not always work.
beyond that, you are entering the realm of free energy calculations and using collective variables, where you would then define a suitable collective variable describing the process you want to observe and then can recover the free energy profile through the applied bias(es).
axel.