Throughout, we use atomic units unless otherwise specified and denote tensors over Cartesian indices using bold font and matrices over an orbital basis with an underline. Since there has been some confusion in the literature regarding the use of the G ′ symbol to indicate the electric dipole-magnetic dipole polarizability with or without the ω -1 factor, we use the notation β = -ω -1 G ′ . Greek indices denote Cartesian coordinates, ω is the frequency of the incident electromagnetic radiation while |ψ j ⟩ and ω j are the j th excited state wave function and excitation frequency, respectively. These definitions for β and A are valid for non-resonant optical activity (ω j / ≈ ω) calculations; resonant optical activity is discussed in greater detail elsewhere. For isotropic media, the observed optical rotation is commonly reported as a normalized quantity in units of deg [dm (g/mL)] -1 , known as specific rotation: