[lammps-users] coupling MD and MC

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1

Hi,

I want to couple Monte Carlo and MD in my simulation inside lammps. I have some experience on MD. I did some basic literature review on Monte Carlo. Can anyone provide me with a small script describing only MC or MD+MC to start with in lammps.

2

Hi,

I want to couple Monte Carlo and MD in my simulation inside lammps\. I

have some experience on MD. I did some basic literature review on Monte
Carlo. Can anyone provide me with a small script describing only MC or MD+MC
to start with in lammps.

your question is not very clear. are you looking for some
(short?) text explaining MC or some example input for MC
in LAMMPS?

the latter is not possible, because LAMMPS does not have
any support for MC.

overall, it is always difficult to answer very general questions.
it would be much easier, if you provide some additional
explanation about what kind of MC you want to do and what
you expect to get out of MC/MD coupling and so on.

cheers,
    axel.

3

I have a nickel-hydrogen system with some initial crack. As diffusion of hydrogen is very less compared to strain rates (10^7 - 10^9), i want to do tension for some timestep (10 picosecond) followed by Monte Carlo (reposition the hydrogen atom to get lower energy of the system as hydrogen will try to form hydrides near the crack) for some timestep ( 10000) then again do deformation followed by MC and so on and so forth. I am looking for some example input in lammps. If lammps doesnot have any such support, i would appreciate if someone can give me some initial example script to start with.

4

You would have to write a fix or command to do the MC
part. The former could be done during a run. The latter
between runs. An example of MC move (for a totally
different applicatoin) that has been added to LAMMPS
is fix bond/swap.

Steve

5

Mehul - just in general, integrating MC into LAMMPS is not a matter of a “script” - it’s a fairly major coding project, and the code depends on what you want to do, which built-in LAMMPS routines you need to access, etc. So unless someone else has done the exact same thing (or “nearly” so), this is something for which you need to learn how the relevant parts of LAMMPS work.

Rob