A simple analytical expression for the charge photogeneration yield (φ) is derived which is based on the Onsager theory of geminate recombination. The expression shows non-Arrhenius temperature (T) dependence φ∼exp(-A/½) with A=2(ezα/4πϵ ϵk)½, where α is a characteristic parameter in the spatial (r) distribution function of thermalized electron-hole pairs g(r) = = (α/4πr2)exp(-αr). The values of α obtained on its basis from the literature experimental data for anthracene crystals are interpreted in terms of collision cross section for primary carriers. The discrete photon energy dependence of α can be explained by crystal anisotropy for the carrier motion.