I am doing adsorption studies and want to add a reservoir in my simulations.
I want to have
1) Adsorbing surface
2) Simulation box containing particles to be adsorbed at a particular
volume fraction.
3) A bulk region from where particles can come into the simulation box as
soon as the particles are absorbed on the surface, to maintain a constant
volume fraction in the simulation box. Also the particles from simulation
box should not move out to the bulk region. Particles in the bulk region
can exert force on the particles in simulation box.
Please let me know if the incorporation of bulk region is possible in
LAMMPS which can behave as mentioned above.
Thanks and regards
Parul Katiyar
Research Scholar
Computational Nano-science Group
Department of Chemical Engineering
Indian Institute of Technology Kanpur
Kanpur, UP, India -208016
I am doing adsorption studies and want to add a reservoir in my simulations.
I want to have
1) Adsorbing surface
2) Simulation box containing particles to be adsorbed at a particular
volume fraction.
3) A bulk region from where particles can come into the simulation box as
soon as the particles are absorbed on the surface, to maintain a constant
volume fraction in the simulation box. Also the particles from simulation
box should not move out to the bulk region. Particles in the bulk region
can exert force on the particles in simulation box.
Please let me know if the incorporation of bulk region is possible in
LAMMPS which can behave as mentioned above.
what LAMMPS can or cannot do is documented in the manual. don't expect
a ready-to-use solution for your problem, but consider it part of your
research to figure out, how you can assemble such a complex procedure
from the available components.
please also see previous discussions on similar subjects. i have the
strong suspicion that your desired setup is more motivated by
macroscopic experiments than a good understanding of the microscopic
processes and thus that a meaningful adsorption simulation would be
much simpler. i honestly cannot imagine the reasoning behind your
requirements, many seem quite arbitrary and not exactly physically
meaningful for a atomistic simulation.
If I remember correctly, I have seen simulations that sound similar to
what you are describing in mixtures of hydrocarbons and water. (There
was no surface in that case.) The simulation was periodic in all 3
directions. There was a thick slab of bulk water, and a slab of oil
(?), which acted as a reservoir. The two liquids naturally phase
separate, so there was no need to add any extra artificial forces to
keep the slab of oil in place. But some of the hydrocarbons do
dissolve into the water, and this concentration is maintained by the
reservoir.
If this example is similar to what you are asking for, then, yes I
don't see why this could not be simulated in LAMMPS (or other MD
programs).
For individual particles, you can make slabs of particles arranged
periodically using the "region", "lattice", and "create_atom" commands
in LAMMPS itself:
On the other hand, if you plan to simulate molecules (as in the
example), you will need to create a DATA file (in addition to an input
script). Some tools for doing this are listed here: