Yihui Wei1,Emily Nienhuis2,Sebastian Mergelsberg2,Trent Graham2,Gregory Schenter2,Carolyn Pearce2,3,Aurora Clark1,2
The University of Utah1,Pacific Northwest National Laboratory2,Washington State University3
Yihui Wei1,Emily Nienhuis2,Sebastian Mergelsberg2,Trent Graham2,Gregory Schenter2,Carolyn Pearce2,3,Aurora Clark1,2
The University of Utah1,Pacific Northwest National Laboratory2,Washington State University3
Relating electrolyte solution structure, from local solvation to that of the extended ion networks, to the solubility and reactivity is of interest due to its relevance in the processing of industrial wastes. X-ray total scattering, for pair distribution function analysis, is one key method to access structures across multiple length scales in these materials, while readily allowing for complementary experimental and computational efforts. In this work we used computation methods to unravel the molecular origin of multiscale correlations observed in the experimentally obtained X-ray pair distribution functions of dilute to concentrated NaNO<sub>2</sub> and NaNO<sub>3</sub> aqueous solutions. Two graph theory approaches, polyhedra identification and geodesic pathway analysis, combined with Molecular Dynamics simulations were utilized to identify the organizational motifs composed of intermolecular networks and their concentration-dependent evolution. The growing population of extended ion networks is found to be responsible for the change of atom pair correlations while bulk water structure remains unperturbed.