Coupled channel distorted wave method of atom--molecule reactive scattering: Application to para to ortho hydrogen molecule conversion
We present a three dimensional coupled channel distorted wave approach of the atom--molecule reactive scattering. The full entrance channel wave functions are obtained from the inelastic vibrational and rotational close-coupling approximation, and reactive cross sections are evaluated with those wave functions employing the transition matrix (T matrix) method. Therefore, in contrast to the previous adiabatic distorted wave model of the reactive scattering, the present method allows for the target molecule to be dynamically distorted following the motion of the incident atom. The formulation of the approach and efficient computational procedures for obtaining the reactive T matrix elements are presented. The reactive scattering cross sections and the rate constants of the H+H/sub 2/ para to ortho hydrogen molecule conversion have been evaluated to illustrate the computational aspects of the present method. The wave function obtained from the rotational close-coupling approximation yields better results on the reactive cross section than that from the pure vibrational coupling. The wave function computed from the simultaneous vibrational and rotational close-coupling approximation results in the most accurate cross section. This indicates that in order to obtain accurate results with the T matrix method, the simultaneous vibrational and rotational distortions of the target molecule should be considered when approximating the full entrance channel wave function.
- Research Organization:
- Department of Physics, University of California, Riverside, California 92521, and Department of Physics, Pacific Lutheran University, Tacoma, Washington 98447
- OSTI ID:
- 6298183
- Journal Information:
- J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 81:11; ISSN JCPSA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Adiabatic T matrix theory for three dimensional reactive scattering: Application to the (H, H/sub 2/) system
Ab initio calculations of processes in low-energy electron-molecule scattering