Purpose

From Positions and Velocities of individual atoms, calculate the centre of mass, centre of mass velocity, the orientation, and the orientation conjugate momentum.

Reconstitute a rigid body that has been split over periodic boundaries

Calculate the current angular velocity of rigid body i, in body frame

Calculate the current angular velocity of rigid body i, in body frame

Calculate the current torque on the rigid body i, in body frame

Add rigid bodies to the DynamicalSystem

Correct the positions of all the atoms in rigid bodies