Quasi-classical trajectory calculations of cross sections and rate constants for the Si + OH → SiO + H reaction

We report the first theoretical determination of cross sections and rate constants for the Si + OH → SiO + H reaction based on dynamics calculations. Quasi-classical trajectory calculations have been carried out for several rotational states of OH using an ab initio potential energy surface recently developed for the X2A′ ground electronic state of SiOH/HSiO. The cross sections behave with collision energies as expected for a barrierless reaction and are slightly sensitive to the rotational excitation of OH. The thermal rate constants evaluated over the range 10–1000 K show a marked temperature dependence below 200 K with a maximum value of 4.3 × 10−10 cm3 s−1 at 20 K.