Extensive and systematic calculations for energy levels and lifetimes are carried out for the lowest 145 levels arising from the 3s²3p⁴, 3s3p⁵, 3s²3p³3d, 3p⁶, 3s3p⁴3d and 3s²3p²3 d² configurations in S-like Kr XXI ion using the multiconfiguration Dirac-Fock (MCDF) method. Additionally, radiative data such as transition wavelengths, absorption oscillator strengths, line strengths and radiative decay rates have also been computed for electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1) and magnetic quadrupole (M2) transitions from the ground state. The importance of Breit interaction (BI) and quantum electrodynamics (QED) corrections on the energy levels has also been estimated. To assess the credibility and integrity of our MCDF energies, independent calculations using the relativistic configuration interaction (RCI) approach have also been performed. Detailed comparisons are made between our two sets of results, as well as with other existing experimental and theoretical values, and a good agreement is achieved. The present results will be helpful for the modeling and diagnostics of fusion plasmas.

对由 3s ² 3p ⁴ , 3s3p ⁵ , 3s ² 3p ³ 3d, 3p ⁶ , 3s3p ⁴ 3d 和 3s ² 3p ² 3 d ²产生的最低 145 个能级和寿命进行了广泛而系统的计算使用多配置 Dirac-Fock (MCDF) 方法在 S 类 Kr XXI 离子中配置。此外，还计算了电偶极 (E1)、电四极 (E2)、磁偶极 (M1) 和磁四极 (M2) 跃迁的辐射数据，如跃迁波长、吸收振荡器强度、线强度和辐射衰减率。基态。还估计了 Breit 相互作用 (BI) 和量子电动力学 (QED) 校正对能级的重要性。为了评估我们的 MCDF 能量的可信度和完整性，还执行了使用相对论配置相互作用 (RCI) 方法的独立计算。我们对两组结果以及其他现有的实验和理论值进行了详细比较，并达成了良好的协议。目前的结果将有助于聚变等离子体的建模和诊断。