Relativistic atomic structure calculations and electron impact excitations of Fe23+

Fully relativistic many-body perturbation energies, transition properties, and lifetimes of lithium-like iron Fe XXIV

“…Notably, the largest deviations occur for the 2p 1/2 and 2p 3/2 levels, with deviations of approximately 1.5% and 1.9%, respectively. In contrast, the GRASP2K results from El-Maaref2016 [24] and the GRASP0 results from Aggarwal2012 demonstrate good agreements with the NIST energies, with most results matching within 0.03%. The deviations for the 2p 1/2 and 2p 3/2 levels are slightly larger, around 0.1% and 0.05% for El-Maaref2016, and around 0.4% and 0.2% for Ag-garwal2012.…”

“…Theoretical energies comparisons with the NIST ones. The theoretical energies are the results from present RMBPT and MCDHF/RCI methods, and those from El-Maaref2016, [24] Aggarwal2012, [8] and Nahar1999. [28,38] To make the figure clearer, the original energy ratio of Key = 2 and 3 (i.e., 2p 1/2 and 2p 3/2 levels) from Nahar1999 are +0.01 and −0.015, respectively.…”

“…Due to the importance of lithium-like ions, there have been many studies on the ions. [3,[6][7][8][9][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] In particular, Nahar et al [28] (hereafter referred to as Nahar1999) used the quasi-relativistic Breit-Pauli R-matrix method (BPRM) to calculate E1 transition radiative rates between energy levels up to n = 10 for lithium-like iron. In their calculations, they just added one-body relativistic correction terms to the non-relativistic Hamiltonian, [31] which included the one-body mass correction, the one-body Darwin term, and the spin-orbit term, they did not even include the two-body interactions in the Breit-Pauli approximation (such as the spin-other orbit, spin-spin, orbit-orbit, two-body Darwin, and spin-contact terms).…”

“…Therefore, it is crucial to enhance the results of Aggarwal2012 by further incorporating the n = 6 energy levels in the calculations, as demonstrated in the present study. In 2016, El-Maaref [24] (denoted as El-Maaref2016) provided lifetimes of 1s 2 nl configurations (where n = 2-6 and l = 0, . .…”

“…However, unfortunately, although El-Maaref2016 employed an advanced fully relativistic method (MCDHF), the lifetimes of El-Maaref2016 in the "Table 3" [24] are significantly different from the fully relativistic lifetimes of Aggarwal2012 [8] and the quasi-relativistic ones of Nahar1999. [28,38] For example, among the 30 reported lifetime values, 20, 14, 10, and 7 have differences with Nahar1999 exceeding 2%, 5%, 10%, and 20%, respectively.…”