  The interaction between vortex beams and rigid molecule is investigated via
calculating the transition amplitudes between the molecular states of different
angular momentum configurations. The result illustrates that vortex beams can
transfer orbital and spin angular momentum to the molecular internal state with
some specific selection rules, which shows its potential in quantum computing
for changing the angular momentum of functional groups at different positions
of a molecule with the position-dependent transition rates. The cases of
interaction with non-canonical vortex beams and of when the molecule is not
very far from the optical vortices are also discussed.
