[lammps-users] Regarding the damping time in fix langevin

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1

Dear all,
I am trying to simulate Brownian diffusion of 10 Å spherical particles using the NVE + Langevin fix.
I also tried the fix Brownian package. I understood that the damping factor in this command originates from gamma_t = 6πηr (The isotropic translational viscous damping).
I cannot understand how to relate the damping from a solvent to that of the damping parameter (time) in the fix Langevin command. Can someone please help me understand the relationship between the two? For reference, I have attached both the input files.

Any help would be much appreciated.
Thank you. Regards,
Ruchir.

LAMMPS_inp_fix_langevin (1.31 KB)

LAMMPS_inp_fix_brownian (938 Bytes)

2

All the information you are looking for is available in the LAMMPS manual or in the publications cited by it.
Specifically for the “damp” parameter, the documentation of fix langevin refers to a discussion in the documentation of fix viscous.

If you need tutoring beyond that, you should probably ask your advisor for advice and assistance.