The interaction of a pulsed circularly polarized laser with the enantiomers of a chiral molecule is described within the rotating-wave approximation as a means for studying the possibility of separating chiral species from a racemic mixture. For freely tumbling molecules, it is found that the separation efficiency depends on the magnitude of electric and magnetic transition dipole moments, and on the angle between them. The method is applied to evaluating the separation efficiency of five small organic molecules, whose molecular properties are computed by time-dependent density functional theory. By choosing an appropriate transition, the efficiency of chiral separation can be increased significantly. (c) 2006 Elsevier B.V. All rights reserved.