Some aspects of configuration interaction of the 4f(N) configurations of tripositive lanthanide ions.
Some aspects of configuration interaction of the 4f(N) configurations of tripositive lanthanide ions.
复制标题
DOI：
10.1021/jp507053v
复制
发表时间：
2014-09
期刊：
影响因子：
--
通讯作者：
P. Tanner;Y. Yeung;Lixin Ning
中科院分区：
文献类型：
--
作者：
P. Tanner;Y. Yeung;Lixin Ning
本文研究了稀土离子（Ln（3+））的4f（N）组态与激发态组态相互作用的一些特征。计算得到的Ln（3+）相同宇称4f（N-1）6p、4f（N+1）5 p（5）和4f（N-1）5 f组态的质心能量与4f（N）组态的质心能量之间的关系可用指数函数很好地拟合。在Y_3Al_5O_（12）/Ln（3+）中，Ln（3+）的4f（N）质心能量位于带隙内，Tb（3+）和Yb（3+）的4f（N）质心能量分别位于导带和价带内。在计算Ln（3+）晶体场能量时，通常用唯象哈密顿量拟合组态相互作用参数α、β和γ，但由于能级数据不完整、能级错配和拟合误差等原因，组态相互作用参数α、β和γ在文献中的数值变化很大。对于LaCl_3/Ln（3+），α的83%和β的50%的变化可以用与主要相互作用组态的重心能量差的变化来解释。参数γ与斯莱特参数F（2）密切相关，并且在大多数计算中不能很好地确定。静电关联自旋-其他轨道参数P（2）的值在Ln（3+）系列中随4f（N）和4f（N-1）5 f组态之间的重心差而平滑变化。计算了Pr（3+）的P（k）（k = 2，4和6）值，发现4f → nf激发仅占LaCl 3/Pr（3+）和Y3 Al 5 O 12/Pr（3+）中P（2）值的约65%和35%。因此，配体的作用是重要的，在确定的值，并讨论包括目前的状态的配置相互作用辅助晶体场计算。在晶体中Ln（3+）系列离子的更可靠和完整的能级数据集可用之前，在上述领域不能取得进一步的进展。
Some features of the interaction of the 4f(N) configuration of tripositive lanthanide ions (Ln(3+)) with excited configurations have been investigated. The calculated barycenter energies of the same parity 4f(N-1)6p, 4f(N+1)5p(5), and 4f(N-1)5f configurations for Ln(3+), relative to those of 4f(N), are fitted well by exponential functions. The 4f(N) barycenter energies of Ln(3+) in Y3Al5O12/Ln(3+) lie in the band gap, with the exceptions of Tb(3+) and Yb(3+), where they are situated in the conduction and valence bands, respectively. The configuration interaction parameters α, β, and γ, which are fitted in the usual phenomenological Hamiltonian to calculate the crystal field energies of Ln(3+), exhibit quite variable magnitudes in the literature due to incomplete energy level data sets, energy level misassignments and fitting errors. For LaCl3/Ln(3+), 83% of the variation of α and 50% of that for β can be explained by the change in the difference in barycenter energy with the predominant interacting configuration. The parameter γ is strongly correlated with the Slater parameter F(2) and is not well-determined in most calculations. The values of the electrostatically correlated spin-other orbit parameter P(2) vary smoothly across the Ln(3+) series with the barycenter difference between the 4f(N) and 4f(N-1)5f configurations. Calculations of the P(k) (k = 2, 4, and 6) values for Pr(3+) show that 4f → nf excitations only account for ∼65% of the value of P(2) for LaCl3/Pr(3+) and 35% of that in Y3Al5O12/Pr(3+). The role of the ligand is therefore important in determining the value, and a discussion is included of the present state of configuration-interaction-assisted crystal field calculations. Further progress cannot be made in the above areas until more reliable and complete energy level data sets are available for the Ln(3+) series of ions in crystals.