How to add rotational diffusion part in fix_langevin

LAMMPS LAMMPS Mailing List Mirror
1

Dear Users,
I am new to LAMMPS, actually I want to modify the fix_langevin. I need to add the rotational diffusion part into the Langevin equation along with the normal translation part which is already present. I have already checked the fix_langevin.cpp script but I don’t know which part accounts for the changes I am looking for, So please give me some suggestions to solve this…

Thanks in Advance

-Rahul

2

Dear Users,
   I am new to LAMMPS, actually I want to modify the fix_langevin. I need to add the rotational diffusion part into the Langevin equation along with the normal translation part which is already present. I have already checked the fix_langevin.cpp script but I don't know which part accounts for the changes I am looking for, So please give me some suggestions to solve this...

fix langevin treats every atom as a point particle, which cannot have
a rotation. so what kind of rotation are you talking about?

langevin thermalization of the rotation of rigid bodies, on the other
hand, is already available in the (plain) fix rigid family of fixes

axel.

3

Thanks for your instant response… Actually I mean, is it possible to account for rotational diffusion along with translation (as already defined in Langevin equation) by using LAMMPS and if so how can I include the rotational diffusion in LAMMPS, Is it a good idea to modify fix_langevin.cpp? or I need to find out some other ways to do this…

Dear Users,
I am new to LAMMPS, actually I want to modify the fix_langevin. I need to add the rotational diffusion part into the Langevin equation along with the normal translation part which is already present. I have already checked the fix_langevin.cpp script but I don’t know which part accounts for the changes I am looking for, So please give me some suggestions to solve this…

fix langevin treats every atom as a point particle, which cannot have
a rotation. so what kind of rotation are you talking about?

langevin thermalization of the rotation of rigid bodies, on the other
hand, is already available in the (plain) fix rigid family of fixes

axel.

4

       Thanks for your instant response.... Actually I mean, is it possible to account for rotational diffusion along with translation (as already defined in Langevin equation) by using LAMMPS and if so how can I include the rotational diffusion in LAMMPS, Is it a good idea to modify fix_langevin.cpp? or I need to find out some other ways to do this..

rotation of what? as already mentioned, there is no rotation possible
for point particles, so why try to include it.

axel.