[TFSI] ion pair conformers were performed to obtain the NBO charge distribution (Table . S9 -S12). For the C 1 ion pair conformer, the NBO charge of H 1 (0.25476) is more positive than that of other hydrogen atoms, while the NBO charges of O 1 (-0.98636) is more negative than that of other oxygen/fluorine atoms, which is ascribed stronger to [TFSI] ion pairs in dielectric continuum medium using ωB97x-D/ DGDZVP level of theory and basis set. "LP" for 1-center valence lone pair, "BD" for 2-center bond, "BD*" for 2-center antibond, and, the unstarred and starred labels corresponding to Lewis and non-Lewis NBOs, respectively), a serial number (1, 2,... if there is a single, double,... bond between the pair of atoms), and the atom(s) to which the NBO is affixed.