To provide critical molecular level insights that are hard to capture by experimental characterization techniques, fully atomistic molecular dynamics (MD) simulations are performed with the Large Atomic Molecular Massive Parallel Simulator (LAMMPS) (Figure ). The molecular interaction is described using the polymer-consistent force field (PCFF). Each simulated system consists of 20 PDMS chains, each 21 monomers long, and 20 LiOTf molecules, equivalent to the experimentally characterized structure. A full description of the MD simulation methods is provided in the experimental section and supporting information (section 3). Results for the MD simulated LiOTf and Mix are given in Figure With the equilibrated MD system, we first compare the polymer-salt interaction in Li-OTf and Mix. From the coordination matrices shown in Figure and Figure , Li + tends to interact with different electronegative moieties in the two system. In LiOTf, Li + has a strong tendency to coordinate both with the nitrogen atom on the pyridyl imine group and the oxygen atoms on OTf -. In Mix, Li + preferably interacts with the oxygen atoms on OTf -. It is worth noting that the most favorable lithium coordination is 4 and 5, consistent with previous work by Olsher et al. The geometries of most 4-fold coordination and 5-fold coordination structures are found to be close to tetrahedral and square-pyramidal by visualization with Visual Molecular Dynamics (VMD) software. In addition, the coordination matrix in Figure indicates that Li + barely interacts with the siloxane group on the PDMS backbone. The coordination analysis based on simulation is consistent with our mass spectroscopy experimental result, confirming that the most probable structure is 4-fold coordination, which helps to validate the transferability of the PCFF force field to the PDMS and salt system.