Hello all,
I am trying to simulate the effect of strong electric fields on the surface of metals. An external electric field induces a charge on the metal surface and acts on it, straining the metal. Is there a way for me to simulate this process in LAMMPS? I could just apply a force on the surface, but the problem is, if my surface is not flat and some regions have smaller curvature, there should also be locally greater charge density and hence greater pulling force.
Any help is appreciated.
Kristian Kuppart
Hello all,
I am trying to simulate the effect of strong electric fields on the surface of metals. An external electric field induces a charge on the metal surface and acts on it, straining the metal. Is there a way for me to simulate this process in LAMMPS?
Have you studied this setup with a quantum code? It would be difficult to model the effect of the external field in an empirical model without having anything to calibrate it with. If it is at all possible.
I could just apply a force on the surface, but the problem is, if my surface is not flat and some regions have smaller curvature, there should also be locally greater charge density and hence greater pulling force.
Thank you for your reply. I have not, because the system under investigation is quite large, on the order of few million atoms so that it would be thick enough that different finite size effects would be reduced. One way we have considered is Finite Element analysis for the surface charge, coupled to dynamics in LAMMPS. The Wish List on the LAMMPS website lists, among others "Coupling to finite elements for stress-strain" which states*,* that lammps could then be coupled to finite elements for stress/strain or “other kinds of PDE effects”
Is electrodynamics also meant as part of this package under development?
Best regards,
Kristian Kuppart
Thank you for your reply. I have not, because the system under investigation
is quite large, on the order of few million atoms so that it would be thick
it is good practice to first study an effect like you describe with a
small model. if it is not possible to find a good representation on
this small scale, it would be a waste of time to go to a larger scale.
enough that different finite size effects would be reduced. One way we have
finite size effect are irrelevant in this case, as they would apply to
the empirical model just as well as to the QM calculation. but if you
don't know what is the process on the smallest level, how can you
expect to describe it correctly on a larger scale?
considered is Finite Element analysis for the surface charge, coupled to
dynamics in LAMMPS. The Wish List on the LAMMPS website lists, among others
"Coupling to finite elements for stress-strain" which states, that lammps
could then be coupled to finite elements for stress/strain or "other kinds
that is something completely different and likely more suitable for
the kind of effect you are describing.
of PDE effects"
Is electrodynamics also meant as part of this package under development?
you have to ask the authors of the AtC package this question. ...and
again, you first need a way to parameterize the effect and model that
represents it well enough.
axel.