where ̵ h is the reduced Planck's constant (J s), N A is Avogadro's number, c is the speed of light (m/s), m e is the electron rest mass (kg), and M is the molecular mass (amu). Another common set of units for isotropic OR is deg L dm -1 mol -1 , which can be obtained by multiplying the specific rotation in Eq. 6 by a factor of M /1000. Note that Eq. 6 depends on ω both through the constant prefactor on the right hand side as well through B. For an oriented system, the 3 Tr(B) factor should be replaced by β n , the average of the components of the B tensor that are perpendicular to the direction of the beam. By defining a chiroptical response tensor B 42