  We show that the spectrum and eigenstates of open-shell multicharged atomic
ions near the ionization threshold are chaotic, as a result of extremely high
level densities of multiply excited electron states (1000 levels per eV in Au
24+) and a strong configuration mixing. This complexity enables one to use
statistical methods to analyze the system. The orbital occupation numbers obey
the Fermi-Dirac distribution, and temperature can be introduced. We show that
radiative capture of electrons through the multielectron resonant states is
strongly enhanced compared to the direct radiative recombination.
