Quasiclassical representation of autoionization decay rates in parabolic coordinates

A simple general analytical formula is obtained for autoionization decay ra tes in parabolic quantum numbers for highly excited atomic states. The form ula is applicable for atomic transitions without change of principle quantu m numbers (Deltan = 0 transitions). A quasiclassical approach for electron motion in a Coulomb field as well as for the Clebsh-Gordan coefficient is u sed for justification of the formula. The results obtained are of a univers al type applicable for the description of autoionization decay rates in arb itrary ions with complex cores. A comparison with quantum numerical calcula tion results shows reasonable correspondence between both types of data.