THEORETICAL INVESTIGATION OF THE AR-2-]ARH++H REACTION - SEMICLASSICAL COUPLED WAVEPACKET TREATMENT((J)+H)

The title reaction is investigated using a semiclassical coupled wavep acket method where the hyperspherical radius rho is treated classicall y and the other coordinates quantally. The wavefunction is expanded ov er electronic states, whose potential energy surfaces and couplings ar e determined within a DIMZO framework. Dynamical calculations are perf ormed in a coplanar-like approximation using eight coupled electronic states. State to state reaction cross sections are obtained in the ene rgy range 0.3 eV less than or equal to E less than or equal to 5 eV. A comprehensive analysis of the reaction mechanisms is presented. It sh ows that the collision can be viewed as a two step process: the sharin g of the system between the electronic adiabatic slates, followed by t he reaction along the uncoupled ground adiabatic potential energy surf ace. Two reaction mechanisms are exhibited, one of them occurring at l ow collision energy only.