Triple autoionization of atomic ions

A time-dependent close-coupling method for four-electron atomic systems is formulated to calculate the triple autoionization of atomic ions. Initial excited states are obtained by relaxation of the Schrodinger equation in imaginary time using a Schmidt orthogonalization method involving interior subshells. Autoionization rates are obtained by propagation in real time using projections onto products of bound and continuum single particle states. For the ( 2 s 2 2 p 2 ) excited configuration of the C 2 + atomic ion, we obtain total, double, and triple autoionization rates. The total autoionization rates are in reasonable agreement with single autoionization rates obtained using configuration-average distorted-wave theory.