Perturbed 5snd1,3D2Rydberg series of Sr

The energy levels of the Sr 5snd${\mathrm{}}^{1,3}$ ${\mathit{D}}_2$ Rydberg series have been measured using an autoionization scheme, which provides an excellent opportunity for the application of the multichannel quantum-defect theory (MQDT) to their spectra. MQDT parametrizations of the ${}_{}{}^{1,3}{}_{}{}^{}$ ${\mathit{D}}_2$ bound-state Rydberg series are presented, including calculated term values for these series. Furthermore, it is found that MQDT wave functions that are derived from experimentally determined level energies are capable of predicting such wave-function-sensitive properties as natural radiative lifetimes of Sr 5snd${\mathrm{}}^{1,3}$ ${\mathit{D}}_2$ Rydberg states.