Intermolecular spin relaxation by translational diffusion of spin pairs has been widely used to study the properties of biomolecules in liquids. Notably, solvent paramagnetic relaxation enhancement (sPRE) arising from paramagnetic cosolutes has gained significant attention for various applications in structural biology, including the structural refinement of intrinsically disordered proteins, the elucidation of the molecular mechanisms driving cosolute-induced protein denaturation, and the characterization of residue-specific effective near-surface electrostatic potentials (ENS). Furthermore, sPRE has been extensively applied in magnetic resonance imaging (MRI), where paramagnetic ions, such as Gd(III)-based ions, are used as contrast agents. Among these applications, the transverse sPRE rate (Γ