A THEORETICAL-STUDY OF THE REACTION OF SI+ WITH AMMONIA

The dynamics of the reaction of Si+ with ammonia have been studied by means of an approximate classical trajectory method and RRKM theory, i n combination with accurate computations of the minima and saddle poin ts of the potential energy surface of the (SiNH3)(+) system, made usin g a slightly modified version of the G1 and G2 theories. A statistical factor (1/3) must be used to correct the capture rate, despite the fa ct that two out of three nearly degenerate potential energy surfaces i n the region of the separate reactants are attractive. The dynamical s tudy suggests the reason could be that only half of the attractive sta tes have the right symmetry to undergo isomerization of the ion-molecu le complex formed initially by silicon and ammonia into a HSiNH2+((2)A ') species. Predictions of the reaction rate for a wide range of tempe ratures are provided.