Gauge-origin independent density-functional theory calculations of vibrational Raman optical activity

We present density-functional theory calculations of vibrational Raman optical activity. Gauge-origin independence of the results is ensured by using London atomic orbitals, and the frequency dependence is included by using analytical response theory. The Raman optical activity circular intensity differences are obtained by combining analytical calculations of linear response functions with numerical differentiation with respect to nuclear distortions. The results are compared with experiment, previous Hartree-Fock calculations, and a more recent approximate sum-over-states approach.