REACTIVE COLLISIONS OF ATOMS WITH DIATOMIC-MOLECULES

The theory of the reactive collision of an atom with a diatomic molecu le is formulated in ''democratic'' hyperspherical coordinates. An adia batic ansatz is used to separate the distance coordinate from the angu lar coordinates. The angular eigenvalue problem is solved, using the h yperspherical harmonics as basis functions, while the R-matrix propaga tion method is used to integrate the resulting coupled equations along the distance coordinate. As an example, reactive collision probabilit ies for H + H-2 are computed, using the Por-ter-Karplus surface. The s ymmetry requirements, when dealing with three identical Fermions in th e collision, are considered explicitly.