Negative Ion Resonances

Temporary anion states, or negative ion resonances, sit just above the electron-detachment threshold and play a role in electron-driven chemistry and charge transfer in extended systems. Standard DFT struggles with them because the underlying states are not square-integrable and conventional local exchange–correlation potentials fail at the right asymptotic behaviour.

In a JPCL cover article (Ghosal, Joshi, Voora) we showed that combining exact exchange with the RPA correlation potential, probed by a complex absorbing potential, gives positions and widths far more reliably than purely local treatments. I am extending these nonlocal frameworks to dynamical long-range polarization and to settings where resonances couple to external fields, surfaces, or condensed-phase environments.