Vibrational and rotational coupling effects in the direct scattering of H2 from Cu(111)

We investigate how the coupling between molecular vibration and rotation affects the direct scattering of H-2 from Cu(111) by performing coupled channel calculations, Our calculation results show that the rotational excitation probability of H-2 scattered (vibrationally elastic) in the first vibrationally excited state (nu = 1) increases more rapidly than that of H-2 scattered (vibrationally elastic) in the vibrational ground state (nu = 0) with increasing translational energy in the low translational energy region. Furthermore, the calculation results for the ratio of the probability of H-2 scattered in nu = 1 and rotational state J = 2 to the probability of H-2 scattered in nu = 1 and J = 0 as a function of translational energy qualitatively reproduce the experimental results in the low translational energy region. (C) 1999 Elsevier Science B.V. All rights reserved.