  We report inelastic neutron scattering measurements of crystal field
transitions in PrFeAsO, PrFeAsO0.87F0.13, and NdFeAsO0.85F0.15. Doping with
fluorine produces additional crystal field excitations, providing evidence that
there are two distinct charge environments around the rare earth ions, with
probabilities that are consistent with a random distribution of dopants on the
oxygen sites. The 4f electrons of the Pr3+ and Nd3+ ions have non-magnetic and
magnetic ground states, respectively, indicating that the enhancement of Tc
compared to LaFeAsO1-xFx is not due to rare earth magnetism.
