Excited States and Absorption Spectra of UF6: A RASPT2 Theoretical Study with Spin鈥揙rbit Coupling

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• 作者：Fan Wei ; Guo-Shi Wu ; W. H. Eugen Schwarz ; Jun Li
• 刊名：Journal of Chemical Theory and Computation
• 出版年：2011
• 出版时间：October 11, 2011
• 年：2011
• 卷：7
• 期：10
• 页码：3223-3231
• 全文大小：932K
• 年卷期：v.7,no.10(October 11, 2011)
• ISSN：1549-9626

文摘

Uranium hexafluoride (UF₆) is an important compound in nuclear chemistry. The theoretical investigation of its excited states is difficult due to the large number of uranium valence orbitals and ligand lone pairs. We report here a detailed relativistic quantum chemical investigation of its excited states up to about 10 eV using restricted active space second-order perturbation theory (RASPT2). Scalar and spin鈥搊rbit (SO) relativistic effects are treated by a relativistic small-core pseudopotential. The RASPT2/SO results remain moderately accurate when the electrons in the active space are restricted to single and double excitations. All eight major spectral peaks corresponding to ligand-to-metal charge transfer have been reproduced within an accuracy of about 0.2 eV and are tentatively assigned. We find that BLYP-based hybrid density functional with 35% Hartree鈥揊ock exchange well reproduce the excitation energies of UF₆.