We describe the implementation of a gauge-origin independent, time-dependent linear-response formalism for the calculation of optical rotation using London atomic orbitals and density-functional theory. We test the accuracy of density-functional methods for studying optical rotation on difficult systems by modeling the optical rotation as a function of the dihedral angle. We also report the first linear response coupled-cluster singles-and-doubles results of optical rotation. The B3LYP functional gives reliable results for the optical rotation, even for molecules with nearly degenerate excited electronic states of opposite polarization, (C) 2002 Elsevier Science B.V. All rights reserved.