Electronic structure of actinide

The methods used to describe the electronic structure of actinide compounds must, therefore, be relativistic and must also have the capability to describe complex electronic structures. Such methods will be described in the next section. The main characteristic of successful quantum calculations for such systems is the use of multiconfigurational wave functions that include relativistic effects. These methods have been applied for a large number of molecular systems containing transition metals or actinides, and we shall give several examples from recent studies of such systems. 

Optical Spectra and Electronic Structure of Actinide Ions in Compounds and in Solution, W.T. Camall and H.M. Crosswhite, Argonne National Laboratory, Report ANL-84-90 (August 1985). 

The results we will report here were obtained using gradient-corrected DFT methods with appropriate relativistic corrections. It is our experience, and that of others, that this approach has several distinct advantages for studies of the electronic structure of actinide complexes ... 

Wallace, W.E., A. Elattar, T. Takeshita, VT. Coon, C.A. Bechman and R.S. Craig, 1977, Rare earth and actinide intermetallics as catalysts, in Proc. 2nd Int. Conf. on Electronic Structure of Actinides, Wroclaw, Poland, p. 93. 

The quantum chemical calculation and computational prediction of the behavior of transuranium elements has become very popular recently for being useful in the qualitative understanding of their complicated chemical properties. In order to calculate the electronic structure of actinide compounds, relativistic effects must be taken into account. One of the important... 

The relativistic calculations on the electronic structure of actinide compounds were reviewed by Pyykko (1987). He also reviewed relativistic quantum chemistry in 1988, whereas the relativistic calculations were limited to small molecules containing one heavy atom only (Pyykko 1988). Calculations on the uranyl and neptunyl ions were introduced in the review article. The general information on the computational chemistry of heavy elements and relativistic calculation techniques appear in the book written by Balasubramanian (1997). There are several first-principle approaches to the electronic structure of actinide compounds. The relativistic effective core potential (ECP) and relativistic density functional methods are widely used for complex systems containing actinide elements. Pepper and Bursten (1991) reviewed relativistic quantum chemistry, while Schreckenbach et al. (1999) reviewed density functional calculations on actinide compounds in which theoretical background and application to actinide compounds were described in detail. The Encyclopedia of computational chemistry also contains examples including lanthanide and actinide elements (Schleyer et al. 1998). The various methods for the computational approach to the chemistry of transuranium elements are briefly described and summarized below. 

Semiempirical (INDO) approach. Zerner and coworkers developed the semiempirical, Intermediate Neglect of Differential Overlap (INDO) method for the calculation of electronic structures of actinide complexes (Cory et al. 1994). They presented ground-state resonance parameter sets for the actinide elements from Ac to Pu and applied the INDO parameters to the actinide halides, bis(cyclooctatetraenyl) actinide complexes M(COT)2 (M = Th, Pa, U, Np, Pu), the so-called actinocene and imide/amide complexes of uranium. The semiempirical approach is required for large systems, such as biological molecules containing actinide elements. 

The second review is due to Pepper and Bursten (1991). This review focussed on the electronic structure of actinide-containing molecules. Note that the present chapter complements this in that our chapter is mostly on lanthanide-containing species. Consequently, the reader is referred to the excellent review by Pepper and Bursten (1991) for a comprehensive summary of the electronic structure of actinide-containing species. The review by Pepper and Bursten (1991) contains the details of calculations on actinide hydrides, actinide halides, actinide oxides, cyclopentadienyl-actinide complexes, aetinocenes, metal-metal bonding in actinide systems and miscellaneous other actinide systems. This review also consists of descriptions of theoretical techniques employed to study the actinide-containing molecules. The reader is directed to this review for further details on such calculations on actinide-containing molecules. 

Camall, W.T., and H. Crosswhite, 1985a, Optical spectra and electronic structure of actinide ions in compounds, in The Chemistry of the Actinide Elements, 2nd Ed., Vol. 2, eds J.J. Katz, G.T. Seaboig and L.R. Morss (Chapman and Hall, London) ch. 16. 

Some relevant material is contained in reviews on Qi-actinide chemistry, the electronic structure of actinide-containing molecules, ab initio calculatimis on transition metal organometallics/ a survey on the landiankfes and actinides fm the literature years 1984-6, and alkoxo and aryloxo chemistry of scandium, yttrium, and lanthanoids/ ... 

OPTICAL SPECTRA AND ELECTRONIC STRUCTURE OF ACTINIDE IONS IN COMPOUNDS AND IN SOLUTION ... 

Pepper, M. Bursten, B. E. The electronic structure of actinide-containing molecules A challenge to applied quantum chemistry. Chem. Rev. 91, 719-741 (1991). 

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