The free energy profiles are shown in Fig. . The profiles exhibit a similar shape to the energy profiles obtained in the gas phase, as presented in Fig. and Fig. . As summarized in Table , the global minimum of the free energy decreases with the lowering of the dielectric constant. Furthermore, since the binding free energy remains negative around the minimum, the ability of the Li + ion to bind to TBT is conserved while scaling the correction terms of the interatomic potential by the dielectric constant.