Journal of Chemical Physics, Vol.117, No.2, 593-605, 2002
Flexible transition state theory for a variable reaction coordinate: Derivation of canonical and microcanonical forms with angular momentum conservation
This paper extends work previously presented [J. Chem. Phys. 113, 2648 (2000)] to establish a rigorous expression for the angular momentum resolved microcanonical reactive flux. A kinetic energy expression in terms of the angular momentum, based on the coordinate system described in the above reference, is derived. Analytic integration over momenta conjugate to the coordinates that describe the relative orientation of the fragments is effected at the canonical level. The Laplace transform relation between canonical and microcanonical coefficients is then exploited to yield the angular momentum dependent microcanonical reactive flux. Evaluation of the resulting rate expression involves a numerical integral whose dimension, in most cases, is the same as the integrals in corresponding canonical and standard microcanonical forms.