  In this work, the solvation and electronic structure of the aqueous chloride
ion solution was investigated using Density Functional Theory (DFT) based
\textit{ab initio} molecular dynamics (AIMD). From an analysis of radial
distribution functions, coordination numbers, and solvation structures, we
found that exact exchange ($E_{\rm xx}$) and non-local van der Waals (vdW)
interactions effectively \textit{weaken} the interactions between the Cl$^-$
ion and the first solvation shell. With a Cl-O coordination number in excellent
agreement with experiment, we found that most configurations generated with
vdW-inclusive hybrid DFT exhibit 6-fold coordinated distorted trigonal prism
structures, which is indicative of a significantly disordered first solvation
shell. By performing a series of band structure calculations on configurations
generated from AIMD simulations with varying DFT potentials, we found that the
solvated ion orbital energy levels (unlike the band structure of liquid water)
strongly depend on the underlying molecular structures. In addition, these
orbital energy levels were also significantly affected by the DFT functional
employed for the electronic structure; as the fraction of $E_{\rm xx}$ was
increased, the gap between the highest occupied molecular orbital of Cl$^-$ and
the valence band maximum of liquid water steadily increased towards the
experimental value.
