  The Stokes-Einstein relation (SER) is one of the most robust and widely
employed results from the theory of liquids. Yet sizable deviations can be
observed for self-solvation, which cannot be explained by the standard
hydrodynamic derivation. Here, we revisit the work of Masters and Madden [J.
Chem. Phys. 74, 2450-2459 (1981)], who first solved a statistical mechanics
model of the SER using the projection operator formalism. By generalizing their
analysis to all spatial dimensions and to partially structured solvents, we
identify a potential microscopic origin of some of these deviations. We also
reproduce the SER-like result from the exact dynamics of infinite-dimensional
fluids.
