Geminate ion recombination in anisotropic media. Effects of initial distribution and external field

Recently we presented [Chem. Phys. Lett. 142, 385 (1987)] a method for calculating the diffusion-controlled geminate escape probability of an ion pair in an anisotropic medium. The escape probability depends on both the length and the direction of the initial interion vector, and is reducible to a function of two dimensionless variables describing the overall anisotropy of the medium. In this paper the treatment is extended to include an initial distribution of interion distances and an external field. Inclusion of a field increases the number of independently variable parameters to five: two to describe the anisotropy of the medium and three to describe the intensity and direction of the applied field. It is shown that the effects of including anisotropy are not negligible for the typical case of anthracene and that the slope-to-intercept ratio of the field-dependent escape probability for a spherically averaged distribution depends on the direction of the applied field