A theoretical description of geminal electrical conductivity in the approximation of isolated ion pairs on the basis of a solution to the Smoluchowski equation

A program was developed for numerically solving the Smoluchowski equation with the initial and boundary conditions corresponding to the Onsager problem for an isolated ion pair. The program was tested successfully by comparing the results with the analytic and numerical data available. The probability of pair survival and polarization current in a constant electric field were calculated. Current curves almost always contained an initial local maximum and a local minimum at long times close to the time of the attainment of a stationary current value. The criteria of the appearance of a negative kinetic dependence (polarization current directed oppositely to the field applied in the local minimum region) were substantiated.