Determination of Excited-State Ionization Potentials for Lithium-Like Sequence Using Weakest Bound Electron Potential Model Theory

In this work, the theoretical calculation of excited-state ionization potentials for 1s$\text{}^{2}$2$\text{}_{p}$ $\text{}^{2}$P$\text{}_{1}\text{}_{/}\text{}_{2}$ , 1s$\text{}^{2}$3$\text{}_{s}^{2}$S$\text{}_{1}\text{}_{/}\text{}_{2}$ , 1s$\text{}^{2}$3$\text{}_{d}^{2}$D$\text{}_{1}\text{}_{/}\text{}_{2}$ , 1s$\text{}^{2}$4$\text{}_{s}^{2}$S$\text{}_{1}\text{}_{/}\text{}_{2}$ , 1s$\text{}^{2}$4$\text{}_{p}^{2}$P$\text{}_{1}\text{}_{/}\text{}_{2}$ , and 1s$\text{}^{2}$4$\text{}_{d}^{2}$D$\text{}_{1}\text{}_{/}\text{}_{2}$ iso-spectrum series of lithium-like elements were carried out using a weakest bound electron potential model theory for nuclear charges from Z=3 to Z=18. The Breit-Pauli approximation was used for relativistic contributions. The obtained values are compared with the experimental results from literature. The overall agreement between data obtained in this work and experimental data from literature can appear to be quite good being generally within 0.1% of experimental values.