Rotational alignment in collisions of Li+ with H2(j=0)

Fully state-selected differential and integral rotationally inelastic cross sections have been determined for the 0 →j transitions of Li+/H2 at a total energy of 0·5 eV. Results have been obtained for space frame, body frame and k 1 × k 2 frame quantization. Alignment effects are interpreted in terms of a single rainbow scattering model. A focussing effect due to the anisotropic well is found, confirming conclusions from previous classical trajectory studies. The implications of the present work for approximate methods are considered. In particular, the conventional explanation for the success of the l-dominant approximation for Li+/H2 is shown to be in error and an alternative is proposed. A discrepancy between the alignment behaviour of j = 0 →4, 6 transitions as calculated by quantum and classical mechanics is noted.

[1]  S. Kinnersly.  Accurate body frame approximations for rotationally inelastic Li+/H2 scattering , 1979 .

[2]  M. Alexander.  Polarization in elastic scattering: close-coupling studies on ArN2 , 1978 .

[3]  L. Monchick.  State selected He--HCl collision cross sections , 1977 .

[4]  J. Reuss,et al.  Diffraction undulations in the differential cross sections of H2-Kr calculated for an anisotropic potential , 1977 .

[5]  J. Toennies,et al.  A study of the dynamics of rotational excitation: Quasi-classical phase space density functions for Li+ + H2 at 0.6 eV , 1977 .

[6]  M. Alexander.  Close-coupling studies of the orientation dependence of rotationally inelastic collisions , 1977 .

[7]  D. Kouri,et al.  On the jz‐conserving coupled states approximation: Magnetic transitions and angular distributions in rotating and fixed frames , 1977 .

[8]  M. Alexander,et al.  Rotational alignment in inelastic collisions , 1977 .

[9]  M. Alexander,et al.  Quantum interpretation of fully state‐selected rotationally inelastic collision experiments , 1977 .

[10]  J. Toennies,et al.  Quasi-classical calculations of elastic and rotationally and vibrationally inelastic differential cross sections for Li+ + H2 , 1976 .

[11]  D. Kouri,et al.  Sufficiency conditions for the validity of the jz‐conserving coupled states approximation , 1976 .

[12]  M. Alexander,et al.  A decoupled l‐dominant approximation for ion–molecule and atom–molecule collisions , 1976 .

[13]  M. Child,et al.  Molecular Collision Theory , 1976 .

[14]  M. Alexander,et al.  l‐dominant study of rotationally inelastic Li+–H2 collisions , 1975 .

[15]  M. Alexander,et al.  An l‐dominant simplification of the close‐coupled equations for collisions between atoms and diatomic molecules , 1975 .

[16]  W. Lester,et al.  Theoretical study of inelastic scattering of H2 by Li+ on SCF and CI potential energy surfaces , 1975 .

[17]  D. Kouri,et al.  A coupled-states approximation study of Li+-H2 collisions , 1974 .

[18]  D. Kouri,et al.  Quantum mechanical close coupling approach to molecular collisions. jz ‐conserving coupled states approximation , 1974 .

[19]  W. Lester,et al.  Coupled channel study of rotational excitation of H2 by Li+ collisions , 1973 .

[20]  A. Arthurs,et al.  The theory of scattering by a rigid rotator , 1960, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.