Generalized outer-electron radii of neutral Coulomb atoms

We prove the radius part of the generalized ionization conjecture for neutral nonrelativistic Coulomb atoms with two spin states. For every choice of ground states, the upper and lower large-nuclear-charge limits of the radius defined by an expected exterior electron mass m are both asymptotic to $(81{\pi }^2/2{)}^{1/3}{m}^{-1/3}$ as m tends to infinity.