Photoionization study of K III and Br IV ions in the framework of the modified orbital atomic theory.

Resonance energies and quantum defects are reported for several Rydberg series for K²⁺ and Br³⁺. For K III ions, the [3s²3p⁴ (¹D₂)]nd (²P,²D) and [3s3p⁵ (³P^°_2,0,1)]np, [3s²3p⁴ (¹S₀)]nd (²D_5/2,3/2) Rydberg series originating from the 3s²3p⁵ (²P°_1/2) metastable and 3s²3p⁵ (²P°_3/2) ground states are considered. For Br IV ions, the study is focused on the 4s²4p (¹D₂, ³P₂, ³P₁)nd series originating from the 4s²4p² (¹D₂,³P₂,³P₁) states along with the 4s4p² (³P₁)np and 4s4p² (¹D₂)np states originating from the 4s²4p² (³P₁, ¹D₂) states. Calculations are performed in the framework of the modified atomic orbital theory (MAOT). Precise data are tabulated up to high excited stated n = 40. The results presented in this paper are in excellent agreement with the synchrotron radiation measurements of Alna'Washi et al. (Phys Rev A 90:023417, 2014) on K²⁺ and of Macaluso et al. (J Phys B At Mol Opt Phys 52:145002, 2019) on Br³⁺. These excellent agreements between theory and experiments indicate that the MAOT formalism can be used to report accurate high-lying excited Rydberg series of atomic species for the diagnostic and the modeling of astrophysical or laboratory plasmas. [ABSTRACT FROM AUTHOR]