QUANTUM-MECHANICAL CROSS-SECTIONS FOR THE D+H2 AND H+D2 REACTIVE SYSTEMS - APPLICATION OF THE NEGATIVE IMAGINARY POTENTIALS WITHIN THE J(Z)-APPROXIMATION

We discuss a new quantum-mechanical approximation to calculate atom-diatom exchange state-to-state cross sections. The method is based on the coupling of the j(z) approximation with negative imaginary potentials (NIPs). The NIPs produce absorbing boundary conditions which permit the application of L2 basis sets expressed in terms of Jacobi coordinates of a single arrangement channel. The method is applied to two systems, namely the D+H-2-->HD+H and H+D2-->HD+D reactions. Good agreement with exact quantum mechanical integral cross sections was obtained.