Hello.
I’m trying to simulate the magnetic field effect on a ferrofluid. How can I model a magnetic field acting on the nanoparticles in the lammps(Although simplifications be required)?
Hello.
I'm trying to simulate the magnetic field effect on a ferrofluid. How can I
model a magnetic field acting on the nanoparticles in the lammps(Although
simplifications be required)?
you cannot. at least not without some C++ programming and some proper
research of the published literature.
you will have to figure out what would be a suitable model. it is
unlikely that an atomic scale model will suffice.
once you have found a suitable model and how to derive parameters for
it, you can think about implementing it.
it is unlikely that you can use LAMMPS out of the box.
axel.
Dear Axel ,
Thank for your answer;
But , whereas the dipolar interactions are almost always present in a
magnetic particle system and are typically the most relevant interactions ,
so applying an external force and solving the equations of motion beside
considering the diploar interaction will not be enough (obviously
corrections for vacuum permeability and magnetic moment magnitudes will be
needed)?
Dear Axel ,
Thank for your answer;
But , whereas the dipolar interactions are almost always present in a
magnetic particle system and are typically the most relevant interactions ,
so applying an external force and solving the equations of motion beside
considering the diploar interaction will not be enough (obviously
corrections for vacuum permeability and magnetic moment magnitudes will be
needed)?
i choose to not participate in such highly speculative and
hypothetical conversations.
if you can present an actual published model that has passed
scientific peer review, we can talk about how to implement that into
LAMMPS.
as far as i am concerned, finding an answer to the question you are
posing is part of your "homework" and to topic for a poll of opinions
on a mailing list.
axel.
Dear Axel , Thnak for your answer
Actually it’s not a homework for me . In a paper ( Aminfar, H., Razmara, N. and Mohammadpourfard, M., 2015. Molecular Dynamics Study of Ferrofluid Flow Inside Nanochannels Under Magnetic Fields. Journal of Computational and Theoretical Nanoscience, 12(9), pp.2339-2347.) a set of equations have been used to model the magnetic polar interaction which are completely similar to “pair_style lj/cut/dipole/cut command” equations and i wanted to know that is it possible to use the LAMMPS for or not and is it an option in lammps or not.
But I’m new with lammps and didn’t know that it is an out of box question.
I’m very Sorry and I apologize for my raw and irrelevant question posted to lammps mailing list.
Thanks a lot for answer.
Dear Axel , Thnak for your answer
Actually it's not a homework for me . In a paper ( Aminfar, H., Razmara, N.
and Mohammadpourfard, M., 2015. Molecular Dynamics Study of Ferrofluid Flow
Inside Nanochannels Under Magnetic Fields. Journal of Computational and
Theoretical Nanoscience, 12(9), pp.2339-2347.) a set of equations have been
used to model the magnetic polar interaction which are completely similar to
"pair_style lj/cut/dipole/cut command" equations and i wanted to know that
is it possible to use the LAMMPS for or not and is it an option in lammps or
not.
what is available in LAMMPS is listed in the documentation. whether
this is applicable for your specific case, *is* your job to find out.
there are *so* many different potentials, nobody can memorize all
details about all of them and what they can be applied for and people
are finding new applications for existing potentials all the time. if
the paper you are referring is worth reading/following, then it should
have a description of how the simulations were performed and what
tools, potentials, and parameters were used. then you can compare this
to the LAMMPS documentation and make some tests to confirm that you
can implement what you want to model with LAMMPS. that is what the
documentation is for. nobody can know this up front without this kind
of testing, unless this is a very widely used model/potential (which
it is clearly not). if there is insufficient information in the paper,
the proper way to go about it, would be to contact the authors of the
paper you mentioned and obtain what is missing.
But I'm new with lammps and didn't know that it is an out of box question.
I'm very Sorry and I apologize for my raw and irrelevant question posted to
lammps mailing list.
your question was not irrelevant as such, it was just very ill posed
and incomplete. it is particularly irritating, that you were
withholding relevant information and details, and at the same time
expecting other people to be perfectly familiar (and beyond) with
additional details that you want to know. that is not how mailing
lists work.
since you say you are new to LAMMPS, i strongly recommend to start
learning to use it with simpler models/potentials and becoming
familiar with how to set up simple MD simulations (e.g. liquid noble
gases, simple implicit solvent and/or brownian motion simulations),
before moving on to as complex a system as you desire to simulate. MD
simulations have many "knobs" and "parameters" to set and adjust and
it is not always obvious how to tweak them for a specific system. so
some degree of general practice and level of experience in reproducing
well studied and well understood system is required before moving to a
more complex and more difficult to validate system.
you will also have to figure out a way to implement the impact of the
magnetic field in LAMMPS, especially, if it is not supposed to be a
homogeneous and linear one. but before that, you need to be able to
validate whether you can model the system of interest without the
magnetic field. that will require some time and effort as such.
axel.