[lammps-users] Conservation of angular momentum for a collection of dumbbells

Dear all,

I have a system of 10 dumbbells and I am running a molecular dynamics simulation of this system. I am using fix rigid command to make each dumbbell from two spherical particles. Each sphere of one dumbbell interacts with the spheres of other dumbbells via Lennard Jones potential. Each dumbbell rotates about its own center of mass. However, I am printing the angular momentum of all the 10 dumbbells. But I am not getting angular momentum conservation for the 10 dumbbells.


I assume you mean the sum of the angmom for each individual dumbbell is not conserved?
How are you computing that?

If that’s the case, then have you tried using a smaller timestep? If the dumbbells rotate too
far in a timestep, then you many not get good conservation of angmom or energy.