Commonly used density functional approximations, such as the PBE and B3LYP functionals, often underestimate ionization potentials and electron affinities due to incorrect (generalized) Kohn— Sham [(G)KS] potentials. As a result, valence ionization energies are underestimated be a few eVs while core-ionization energies are underestimated by tens of eVs. A severe consequence is that stable anionic states are predicted to be unbound. Such “loose” electrons are a result of self-interaction errors and a lack of dispersion-type correlation effects in approximate potentials. In this talk, I will discuss my group’s efforts in overcoming these limitations using the random phase approximation (RPA) method, a non-local density functional approach. Using low-scaling algorithms for RPA, I will discuss the importance of non-local correlationsin simulating the electronic structure of molecular anions, hydrated electron, F-center defects and non-resonant X-ray emission spectroscopy.