A Grid-based One-electron Model for Describing Non-valence Correlation Bound Anions in Molecules and Clusters

Non-valence correlation bound (NVCB) anions are bound by dispersion-type correlation between the excess electron and the electrons of a molecule or cluster. The computationally demanding, O(N^5-6), electron attachment equation-of-motion (EA-EOM) method is typically used to describe these species. An alternative, one-electron models, treat only the excess electron explicitly and use classical polarization potentials to capture the molecular density's response. We describe models developed in our group for characterizing NVCB anions and their implementation in our one-electron model code PISCES. To solve the one-electron Schrödinger equation sine discrete variable representation (DVR) grid bases are employed. A mixed real and momentum space method is combined with Fast Fourier transforms. A dual grid approach has been developed too, where an affordable coarse DVR grid is refined via interpolation. We report binding energies in agreement with ab initio EOM calculations at a fraction of the computational time. We are currently working to extend this to the image potential states of graphene using finite model systems.