Over the last decades, computational chemistry has seen continuous and rapid development that is driven both by the sustained development of computer technology (exemplified by Moore’s Law) and by significant advances in theory and methodology. Computational chemistry has reached a point were it can be used as “just another spectrometer” in a “black-box” fashion for certain areas and applications, while it continues its fast development in other areas.
Theoretical and computational actinide chemistry, application of the tools of computational chemistry to the early actinides (typically Th and U to Pu, but increasingly also beyond), is a research topic that is still a frontier area, despite having seen impressive advances over the last several years. This is due to challenges arising from the size of typical systems, the need to include relativistic effects, and technical difficulties such as the large number of closely spaced electronic states, amongst others. This, combined with the experimental challenges of actinide (and particularly trans-uranium) chemistry, makes the actinides a particularly fruitful area for collaborations between theoretical and experimental research.
We will begin this presentation by discussing some aspects of the computational methodology as applied to actinides (and thus, we will briefly “take a look inside the black box”). We will then focus on some applications from our recent work. In this manner, we hope to illustrate the scope of questions that can be addressed, and the kind of unique insight that computational chemistry might provide. Specifically, we will discuss representative results from the following areas:
(i) Macrocycle complexes: Polypyrrolic macrocycles (including a ligand system colloquially known as ‘pacman’ due to its shape) provide access to unique bonding schemes if complexed with one or more actinide atoms;
(ii) Mineral surface interactions: Adsorbtion of uranyl species onto TiO2 surfaces;
(iii) 2D Materials: Surface interactions of uranyl with silicene.
In each case, we will attempt to draw specific as well as general conclusions regarding the methodology employed and the chemistry involved.