Pierloot Kristine, van Besien Els, van Lenthe Erik, Baerends Evert Jan
Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Heverlee-Leuven, Belgium.
J Chem Phys. 2007 May 21;126(19):194311. doi: 10.1063/1.2735297.
The electronic spectra of UO(2) (2+) and UO(2)Cl(4) are calculated with a recently proposed relativistic time-dependent density functional theory method based on the two-component zeroth-order regular approximation for the inclusion of spin-orbit coupling and a noncollinear exchange-correlation functional. All excitations out of the bonding sigma(u) (+) orbital into the nonbonding delta(u) or phi(u) orbitals for UO(2) (2+) and the corresponding excitations for UO(2)Cl(4) are considered. Scalar relativistic vertical excitation energies are compared to values from previous calculations with the CASPT2 method. Two-component adiabatic excitation energies, U-O equilibrium distances, and symmetric stretching frequencies are compared to CASPT2 and combined configuration-interaction and spin-orbit coupling results, as well as to experimental data. The composition of the excited states in terms of the spin-orbit free states is analyzed. The results point to a significant effect of the chlorine ligands on the electronic spectrum, thereby confirming the CASPT2 results: The excitation energies are shifted and a different luminescent state is found.
采用一种最近提出的相对论含时密度泛函理论方法，基于用于包含自旋轨道耦合的二分量零级正则近似和非共线交换相关泛函，计算了UO₂²⁺和[UO₂Cl₄]²⁻的电子光谱。考虑了UO₂²⁺中从成键σu⁺轨道到非键δu或φu轨道的所有激发以及[UO₂Cl₄]²⁻的相应激发。将标量相对论垂直激发能与先前用CASPT2方法计算的值进行比较。将二分量绝热激发能、U - O平衡距离和对称伸缩频率与CASPT2以及组合组态相互作用和自旋轨道耦合结果以及实验数据进行比较。分析了激发态在无自旋轨道态方面的组成。结果表明氯配体对电子光谱有显著影响，从而证实了CASPT2结果：激发能发生了位移，并且发现了不同的发光态。
