NUMERICAL STUDY OF THE REACTION OF CN WITH O-2

The rate of reaction of CN with O-2 has been calculated over the tempe rature range 1 to 3000 K on the basis of (i) ab initio calculations at the G2-level for critical parts of the potential energy surface, (ii) quasi-classical trajectory calculations of the capture rate in a comb ined dipole-quadrupole, dipole-induced dipole and dispersion long-rang e potential, changing to a Morse potential at short range, and (iii) v ariational RRKM-type calculations of the competition between dissociat ion to reactants and crossing a low barrier to products for the NCOO c ollision complex. The results are in fair agreement with experiment ov er the whole temperature range and indicate some areas in which the th eory needs to be improved.