Relativistic Four-Component Quantum Chemical Studies on Actinide Dimers

该项目涉及对所选的鳗系元素二聚体分子U2、Pu2和Am2的量子化学研究，目的是深入了解鳗系元素化学中基本单元的分子成键和电子结构。要做到这一点，必须严格地对待狭义相对论和电子关联，并将它们放在同一基础上。我们应用大规模的相对论四分量多组态自洽场和多参考组态相互作用方法来满足这些要求，并且是专门为详细研究小的重元素分子而发展起来的。将获得的信息包括基态和激发电子态的表征以及精确的光谱性质，如平衡键长、解离能和激发能。在应用研究之外，我们将进一步改进方法，实现平行度和线性对称性以及电子跃迁矩，以便直接与正在进行的关于鳗系元素二聚体的实验研究合作。

The project concerns the quantum-chemical study of selected actinide dimer molecules, U2, Pu2, and Am2, with the aim of gaining a profound understanding of the molecular bonding and the electronic structure of basic ¿units¿ of actinide chemistry. To achieve this, special relativity and electron correlation must be treated with rigor and on the same footing. We apply large-scale relativistic four-component multi-configuration self-consistent-field and multi-reference configuration interaction methods which fulfill these requirements and have been developed particularly for the detailed study of small heavy-element molecules. The information to be obtained covers the characterization of ground and excited electronic states and accurate spectroscopic properties such as equilibrium bond lengths, dissociation and excitation energies. Going beyond the applied studies, we will further improve the methods by implementing parallelism and linear symmetry as well as electronic transition moments for direct cooperation with ongoing experimental investigations on actinide dimers.