Prediction of large differences in diffraction of cold beams of para-H2 and normal-H2 by LiF(001)

The close-coupling wave packet method has been used for performing calculations on rotationally and diffractionally inelastic scattering of H2 from LiF(001), using a model potential. Inclusion of the quadropole-ionic lattice interaction in the model leads to large differences between the diffraction of H2 in its j = 0 rotational state and diffraction of j = 1 H2. For j = 1 1 H2 large probabilities are obtained for changes of the magnetic rotational quantum number mj. It should be possible to verify some of our results by diffraction experiments employing cold beams of para-H2 and normal-H2.