2026-10-14T17:33:00Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34024089 2026-09-29T13:43:19Z category_1 category_4 category_915 category_7 category_13 category_873 category_502 category_734 portal_63 item_type_6 month_year_09_2026

How Ions Reshape the Infrared Spectra of Aqueous NaCl Chenxi Nie (5600816) Ming Yang (109148) Zheng Yu (484983) Chunyi Zhang (335761) Biophysics Biochemistry Physical Sciences not elsewhere classified Medicine Genetics Chemical Sciences not elsewhere classified Astronomical and Space Sciences not elsewhere classified Biological Sciences not elsewhere classified sup >+</ sup deep wannier model – h stretching yet relating spectra spectra semiquantitatively reproduce learning molecular dynamics frequency intensity essential dependent ir spectra aqueous nacl infrared water ir response electrolyte ir spectra experimental blue shift infrared spectra aqueous nacl ir response stretching band molecular mechanisms electrolyte solutions transferable framework strongly constrained spectroscopy probes shell water isosbestic point ionic contributions intensity enhancement electronic polarization combine machine bonded waters bond structure bond network band narrowing appropriately normed adds high Infrared (IR) spectroscopy probes the hydrogen-bond structure of electrolyte solutions, yet relating spectra to molecular mechanisms is challenging. We combine machine-learning molecular dynamics with a deep Wannier model to compute concentration-dependent IR spectra of aqueous NaCl with strongly constrained and appropriately normed (SCAN)-level accuracy. The spectra semiquantitatively reproduce the experimental blue shift, intensity enhancement, band narrowing, and isosbestic point of the O–H stretching band. Dipole-current decomposition reveals two ionic effects. First, ions reshape the water IR response: by disrupting the hydrogen-bond network of first-shell water, they blue-shift the stretching band and suppress its intensity, with Na⁺ more disruptive than Cl^–. Second, ions themselves carry an IR response: the electronic polarization of Cl^–, driven by O–H stretching of its hydrogen-bonded waters, adds high-frequency intensity essential for the isosbestic point. Because both effects are local and additive, spectra at any concentration can be reconstructed from hydration-shell and ionic contributions, a transferable framework for electrolyte IR spectra. 2026-09-29T00:00:00Z Text Journal contribution 10.1021/acs.jpclett.6c02161.s001 https://figshare.com/articles/journal_contribution/How_Ions_Reshape_the_Infrared_Spectra_of_Aqueous_NaCl/34024089 CC BY-NC 4.0