Randomly interchanging the velocities of a group of particles

Dear experts and my fellow users,
is there any way to randomly interchange velocities of solvent particles in SRD or in some other simple LJ simulations? I want to screen hydrodynamics interaction in the SRD simulation by randomly interchanging the solvent velocities after every collision steps!

Dear syed,

as another user of LAMMPS and fix srd, I am not aware of any such option, or at least a reasonable one. I suggest understanding how the source code of fix srd works and deriving an implementation yourself. You would have full control over how you randomize velocities.

Apart from that, you have the option to compare SRD against under- or overdamped Langevin dynamics by using fix langevin or fix brownian. However, I am not too sure how close the comparison would be. There is literature out there doing that, for example 10.1016/j.jcis.2015.07.058.

Best,
November