Systematic investigation of multiple scattering in liquid-phase electron scattering

Understanding the atomic-scale structure of liquids is fundamental to solution phase chemistry, yet its direct characterization remains a challenge. Mega-electron-volt liquid-phase electron scattering (MeV-LES) has emerged as a powerful laboratory-scale technique, but the sample thickness often surpasses the penetration depth of the MeV electron beam, which introduces multiple scattering effects that hamper the scattering data quality. Here, we employ a state-of-the-art MeV-LES platform to systematically investigate the structures of thirteen chemically diverse solvents, providing a crucial benchmark library of atomic correlations. Our high-resolution data reveal a significant sample-dependent discrepancy between experimental results and simulations. By comparing with molecular dynamics simulation results, we demonstrate that this discrepancy originates from multiple scattering and is strictly governed by the solvent’s intrinsic short-range structural ordering. While simple liquids like water exhibit short-range order only within 8 Å, many organic solvents possess persistent order extending 15–20 Å. Such an extended order generates a very sharp first liquid peak in the reciprocal space, thereby rendering the solvent highly susceptible to multiple scattering artifacts. These advances provide a key perspective in understanding liquid-phase electron scattering data, paving the way for accurate analyses of complex molecular systems.