In the case of solvent molecules, solvent dimensions are obtained using a custom size metric built on SMORES 33 (Figure ), an extension of convenVonal steric parameters, Sterimol. Here, we require a method that assesses all of the dimensions of the solvent molecule and, in doing so, the resulVng distribuVon of solvent dimensions may be considered a measure of "shape". Importantly, considering the complex solvent-cage interacVon dynamics for candidate solvent molecules, we treat rigid and non-rigid candidate solvent molecules differently; the enVre solvent molecule is considered for rigid candidates, whereas slices of the solvent molecules are considered for non-rigid candidates (Figure ). Full details on calculaVng this metric are found in SupporVng InformaVon SecVon S5.2. Figure depicts the KDE for two candidate solvents, 15-crown-5 and chloroform, and further illustrates the unique characterisVcs of the custom size metric that we present. Here, chloroform is represented by a bimodal distribuVon, which indicates that the chloroform molecule shape is dominated by two main vectors -the Cl-Cl vector and the Cl-H vector. On the other extreme, 15-crown-5 is represented by a wide, unimodal distribuVon, reflecVng the underlying symmetry of the molecule.