Fix langevin with thermostating of rotational dof

Dear experts, I am trying to educate myself about the number 3/10 used to scale the rotational damping parameter. I don’t see any reference for such scaling on its page. I know in literature people use Dr = 3Dt / size^2, for simulations of spherical colloidal suspension. Is this 3/10 about the relation between rotational and translational diffusion coefficients?