A method for carrying out quasiclassical trajectory (QCT) calculations of A + BC(upsilon ,j) reactive collisions for the special case of the total angular momentum J = 0 is described. Since quantum reactive scattering calculations involving heavier atoms are not straightforward for the J>0 case, this method is useful to establish the extent to which classical mechanics is applicable to a particular reaction. The method is tested by comparing the results of trajectory calculations for the J = 0 case with analogous quantum-mechanical (QM) calculations for the O(P-3) + HCl reaction and the reverse reaction Cl(P-2) + OH. The S4 potential surface, which is based on MRCI+Q/cc-pVTZ energies scaled by the scaled external correlation method [B. Ramachandran et al., J. Chem. Phys. 111, 3862 (1999)], is used for these calculations. The QCT and QM cumulative reaction probabilities are found to be in good agreement, especially for the Cl + OH reaction. The agreement between the two types of state-resolved reaction probabilities is less striking but improves considerably as the initial diatomic rotational quantum number j increases. A comparison is also made between the exact and J-shifted QCT thermal rate coefficients. These are found to be in excellent agreement, which is in keeping with similar agreement observed in the case of the quantum-mechanical exact and J-shifted thermal rate coefficients. (C) 2001 American Institute of Physics.