where E AIMD is the energy of the quantum region, E cDFT is the energy of mesoscopic region, and E AIMD/cDFT is the coupling energy between two regions. For the AIMD calculation, which is performed using our plane-wave code, the energy is minimized with respect to the electronic density. For the cDFT part, we input initial ion densities and potentials, solve the Poisson equation for the new potentials and thus update the ion densities. This cycle is done self-consistently. For electrostatic coupling, there are several ways to implement the coupling between AIMD and cDFT where the electric field from cDFT interacts with the AIMD atoms. We have explored several approaches, and we settled on modeling the AIMD electronic density as augmented point charges or Blöchl atomic point charges, which are shown to be successful with COSMO. The coupling energy E AIMD-cDFT between AIMD and cDFT models is calculated as