First described by Pauling, 1 a two-center, threeelectron (2c-3e) "hemibond" is formed when a doublyoccupied frontier orbital of one molecule overlaps favorably with the half-filled orbital of a radical, resulting in a stabilizing interaction with a bond order of 1/2. Computational evidence for the existence of hemibonds has been put forward in a variety of systems, and hemibonding has long been discussed in the context of aqueous-phase pulse radiolysis experiments involving sulfur-containing species. Definitive experimental evidence for hemibonds exists only in a few cases, however, including (H 2 S) + n , (CH 3 SH) + 2 , (CH 3 S) + 2 , 17 [(CH 3 ) 2 S] + 2 , 18 Cl• • • NH 3 , and a few other systems. Hemibonding in OH(aq) was predicted in some of the earliest ab initio molecular dynamics (ai MD) simulations using density functional theory (DFT), but these predictions were quickly rejected as artifacts of selfinteraction error (SIE) associated with the use of semilocal functionals, since SIE is known to overstabilize 2c-3e bonds. More recently, it has been suggested that the hemibonds observed in those early simulations might instead be artifacts of a too-small periodic simulation cell. Perhaps for these reasons, the possibility of a hemibonded solvation motif seems not to have been considered in the analysis of recent x-ray experiments on OH(aq). Recent ai MD simulations using hybrid functionals report no evidence of the feature traditionally associated with this motif, namely, a peak at 2.2-2.3 Å in the radial distribution function (RDF) for oxygen. In the present work, we use periodic DFT simulations at the PBE0 + D3 level to demonstrate that the disappearance of this feature in hybrid DFT does not imply the absence of a hemibonded solvation motif. In contrast to what has become conventional wisdom, spin delocalization persists even in the presence of 25% ex- * herbert@chemistry.ohio-state.edu act exchange, and hemibond-like configurations prove to be crucial in explaining the electronic absorption spectroscopy of OH(aq).