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, in combination with accurate computations of the minima and saddle points of the potential energy surface of the (SiNH3)+ system, made using a slightly modified version of the G1 and G2 theories. A statistical factor (13) must be used to correct the capture rate, despite the fact that two out of three nearly degenerate potential energy surfaces in the region of the separate reactants are attractive. The dynamical study suggests the reason could be that only half of the attractive states have the right symmetry to undergo isomerization of the ion-molecule complex formed initially by silicon and ammonia into a HSiNH2+(2A′) species. Predictions of the reaction rate for a wide range of temperatures are provided.