Origin invariant calculation of optical rotation without recourse to London orbitals

We propose an inherently origin invariant formulation of specific optical rotation obtained from the conventional velocity gauge expression by subtracting the static limit from the electric dipole-magnetic dipole polarizability: <<(p) over right arrow, (L) over right arrow >>(omega) --> <<(p) over right arrow, (L) over right arrow >>(omega) - <<(p) over right arrow, (L) over right arrow >>(0). London (gauge including) atomic orbitals are therefore not needed to ensure origin invariance and, consequently, this modified velocity gauge formulation may be employed in conjunction with variational and non-variational quantum chemical methods alike. Sample calculations on S-propylene oxide and 3,4-methylenedioxymethamphetamine using self-consistent field and coupled cluster wave functions underline this point and show that the basis set convergence of the modified velocity gauge formulation is similar to the conventional length gauge and London expressions. (C) 2004 Elsevier B.V. All rights reserved.