Green's-function treatment of Rydberg molecules with spins

The authors present a method based on the Coulomb Green's function to derive the electronic structure of ultra-long-range Rydberg molecules including spins, providing a promising alternative to the standard method based on basis-set expansion, which was shown to have serious convergence problems. Use of this approach should enable more accurate studies of Rydberg-molecule spectra and the electron-atom scattering phase shifts upon which they depend.