Integral and differential cross sections for the Li+HF→LiF+H process. A comparison between jz quantum mechanical and experimental results

Abstract In this work is presented a detailed quantum mechanical study of the Li+HF( v =0, j )→LiF( v ′, j ′)+H reaction in the low-energy region 0.001⩽ E tr ⩽0.15 eV. The theoretical-numerical treatment was carried out within the inelastic j z approximation coupled with negative imaginary potentials (to form absorbing boundary conditions) to account for the reactivity of the system. Integral and differential state-to-state cross sections were calculated and compared with experiment and other calculations. As for the experiments, (a) the theoretical treatment approximately reproduced the laboratory measured differential cross sections and (b) produced integral cross sections in the range 0.30⩽σ⩽0.65 A 2 , which overlap with the measured value (at E tr =0.13 eV) of σ=0.6±0.30 A 2 .

[1]  D. Kouri,et al.  Scattered wave variational principle for atom—diatom reactive scattering: hybrid basis set calculations , 1991 .

[2]  J. N. Murrell,et al.  Analytical potentials for triatomic molecules: VII. Application to repulsive surfaces , 1980 .

[3]  H. Loesch,et al.  Huge steric effect in the reaction Li+HF(v=1, j=1)→LiF+H , 1991 .

[4]  R. T. Pack.  Space‐fixed vs body‐fixed axes in atom‐diatomic molecule scattering. Sudden approximations , 1974 .

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

[6]  Antonio Laganà,et al.  A quasiclassical trajectory test for a potential energy surface of the Li+HF reaction , 1982 .

[7]  A. Baram,et al.  The application of Toeplitz matrices to scattering problems , 1993 .

[8]  H. Loesch.  A sliding mass model to rationalize effects of reagent rotation on reaction cross sections , 1986 .

[9]  F. Stienkemeier,et al.  Evidence for the deep potential well of Li+HF from backward glory scattering , 1993 .

[10]  R. Wyatt,et al.  Differential reaction cross sections in the bending corrected rotating non-linear model: Li + HF → LiF + H , 1987 .

[11]  A. Baram,et al.  Quantum-mechanical cross sections for the D + H2 and H + D2 reactive systems. Application of the negative imaginary potentials within the jz approximation , 1993 .

[12]  F. Stienkemeier,et al.  Steric effects in the state specific reaction Li+HF (v=1, j=1, m=0)→LiF+H , 1993 .

[13]  Antonio Laganà,et al.  Accurate 3D quantum reactive probabilities of Li+FH , 1993 .

[14]  Hiroki Nakamura,et al.  Variational principles for reactive collisions based on the generalized Lagrange multiplier method , 1992 .

[15]  G. A. Parker,et al.  Li+FH reactive cross sections from J=0 accurate quantum reactivity , 1993 .

[16]  M. Baer.  Variational (time-independent) calculations of reactive S matrix elements: application of negative imaginary absorbing potentials and contracted L2 basis sets , 1992 .

[17]  Christopher H. Becker,et al.  Study of the reaction dynamics of Li+HF, HCl by the crossed molecular beams method , 1980 .

[18]  M. Shapiro,et al.  A classical mechanical study of the LiFH system , 1981 .

[19]  Antonio Laganà,et al.  An accurate evaluation of the stationary points of the LiFH potential energy surface , 1989 .

[20]  William H. Miller,et al.  A new basis set method for quantum scattering calculations , 1987 .

[21]  William H. Miller,et al.  Quantum scattering via the S‐matrix version of the Kohn variational principle , 1988 .

[22]  W. B. Miller,et al.  Exchange reactions of alkali atoms with alkali halides: a collision complex mechanism , 1967 .

[23]  A. Baram,et al.  Exact quantum mechanical three-dimensional reactive probabilities for the D + H2 system: variational calculations based on negative imaginary absorbing potentials , 1992 .

[24]  M. Baer.  Selection rules and quasi selection rules in three-body exchange reactions , 1973 .

[25]  M. Shapiro,et al.  The approximate conservation of P-helicity in rotational excitation: A new decoupling scheme , 1975 .

[26]  R. Levine,et al.  A classical kinematic model for direct reactions of oriented reagents , 1987 .

[27]  D. Neuhauser,et al.  The application of negative imaginary arrangement decoupling potentials to reactive scattering: Conversion of a reactive scattering problem into a bound-type problem , 1992 .

[28]  D. Kouri,et al.  Theory of Reactive Scattering. IV. Exact Quantum Mechanical Study of Angular Independent and Angular Dependent Models for Three Dimensional Rearrangement Collisions , 1972 .

[29]  Donald J. Kouri,et al.  Theory of Reactive Scattering. II. Application of the τ Operator Formalism to a Linear Model for Three Body Rearrangements , 1972 .

[30]  P. Aker,et al.  Quasiclassical trajectory studies of the hydrogen atom + hydrogen iodide .fwdarw. hydrogen iodide (v',j') + hydrogen atom energy-transfer and exchange reaction at high collision energy , 1993 .

[31]  D. Neuhauser,et al.  The application of wave packets to reactive atom–diatom systems: A new approach , 1989 .

[32]  A. Baram,et al.  Three-dimensional reactive quantum mechanical study for the hydrogen atom + X2 (X = H, D, T) systems: application of negative imaginary arrangement decoupling potentials , 1993 .

[33]  Henry F. Schaefer,et al.  Potential energy surface for the Li+HF. -->. LiF+H reaction , 1980 .