Chemical Physics ( IF 2.0 ) Pub Date : 2020-03-31 , DOI: 10.1016/j.chemphys.2020.110781 Soumendra K. Roy , Rajendra Prasad
The relativistic all-electron ab initio calculations have been performed on 5f3 manifold of free U3+ ion to explore the electronic structure and spectra. The spin-orbit-free low lying electronic states have been calculated at the level of theories of State-Averaged Complete Active Space Self-Consistent Field (SA-CASSCF) and Multi-State Complete Active Space Second-Order Perturbation (MS-CASPT2) using different sets of active orbitals. The corresponding spin-orbit states and the energy levels have been computed using Douglas-Kroll type of atomic mean-field integral (AMFI) approach. The ground state is 4I9/2 and the electron correlation has been found to be small in case of the excited 4I states. The low-lying energy levels obtained with the core-valence correlation effects in the treatment are in very good agreement with the experimental values.
中文翻译:
U 3+离子多重电子结构的相对论全电子从头算
在自由U 3+离子的5f 3流形上进行了相对论的全电子从头计算,以探索电子结构和光谱。在状态平均完整有源空间自洽场(SA-CASSCF)和多状态完整有源空间二阶扰动(MS-CASPT2)的理论水平上计算了无自旋轨道的低躺电子状态。使用不同组的活动轨道。相应的自旋轨道状态和能级已使用Douglas-Kroll类型的原子平均场积分(AMFI)方法进行了计算。基态为4 I 9/2,并且发现在激发4的情况下电子相关性很小我说。在治疗中具有核心价相关效应的低能级水平与实验值非常吻合。