Ramirez Gerardo, Sunga Felizsa, Tilson Jeffrey L, Ermler Walter C
Department of Chemistry, The University of Texas at San Antonio, San Antonio, TX 78249, United States of America.
Renaissance Computing Institute, University of North Carolina at Chapel Hill, Durham, NC 27517, United States of America.
J Phys Condens Matter. 2022 Jun 24;34(34). doi: 10.1088/1361-648X/ac7930.
Relativistic calculations of the structural and spectral properties of the PbO molecule can provide fundamental information about the importance of a proper treatment of angular momentum coupling among electrons in order to achieve accurate computational results for spectral properties. Specifically, the nature of these couplings in PbO is expected to be intermediate between the- and-coupling limits because of its light/heavy element composition. This article reports potential energy curves, transition energies, electric dipole transition moments, permanent dipole moments and spectroscopic constants of PbO calculated using a multireference single plus double excitations spin-orbit configuration interaction approach in the context of relativistic effective core potentials and their concomitant spin-orbit coupling operators. The calculated results are in general agreement with both available experimental results as well as earlier calculations. New values for properties of excited states are also reported. It is noteworthy that certain properties show larger deviations from previous calculations. These deviations are attributed to direct and indirect relativistic effects resulting from diatomic electron-electron angular momentum coupling effects, which are included consistently in the calculations reported herein.
对PbO分子的结构和光谱性质进行相对论计算，可以提供关于正确处理电子间角动量耦合的重要性的基本信息，以便获得光谱性质的精确计算结果。具体而言，由于PbO的轻/重元素组成，预计其这些耦合的性质介于j-j和l-s耦合极限之间。本文报道了在相对论有效核势及其伴随的自旋轨道耦合算符的背景下，使用多参考单重加双重激发自旋轨道组态相互作用方法计算得到的PbO的势能曲线、跃迁能量、电偶极跃迁矩、永久偶极矩和光谱常数。计算结果总体上与现有的实验结果以及早期的计算结果一致。还报道了激发态性质的新值。值得注意的是，某些性质与先前的计算结果存在较大偏差。这些偏差归因于双原子电子-电子角动量耦合效应产生的直接和间接相对论效应，本文报道的计算中一致包含了这些效应。
