Dear LAMMPS users,
I am working on a hybrid MD/MC algorithm that involves rigid bodies by using a python wrapper script. Each monte carlo step requires reinitialization of velocities (for the case of rigid bodies, 3 linear and 3 angular center of mass (COM) velocities should be drawn from Maxwell-Boltzmann distribution.)
Upon examination of the source code and the relevant paper describing the algorithm (Miller), I found that Lammps calculates the COM positions, rotations and velocities from the initial particle positions and velocities at the start of the first run after the fix is defined, then the rotations and angular momenta are updated internally. For my case, I want to be able to update these internal COM linear and angular velocities directly at the start of each monte carlo step.
I was wondering if there is a way to manually alter the COM velocities of each body using the python library interface. I checked the previous relevant threads in the e-mail list, but could not find an answer to my specific question. I know that some per-atom properties can be manually updated using the scatter_atoms command, but not sure if this can be applied to per-body properties.
Any input would be greatly appreciated.