A Green-Kubo formula for the sedimentation coefficients

By applying linear response theory to mechanical perturbations, a new Green-Kubo-type formula for the sedimentation coefficients is derived. All species are treated on the same footing, and the dependence of the sedimentation coefficient on the reference frame is carefully taken into account. The connection between the sedimentation and the interdiffusion (or mutual diffusion) coefficients is examined from a microscopic point of view for a two component system, and it is shown that the Svedberg relation follows from the present results by a simple microscopic reference frame transformation.