二维材料在物理、化学和材料科学等领域表现出优异的性能，因此设计、预测和合成新型二维材料变得尤为重要。随着理论计算预测工具的发展，许多由s区、p区和d区元素组成的二维材料被预测可以稳定存在，其中一些已经通过实验成功合成。然而，对于包含f区元素二维材料的相关研究却相对罕见。铀元素是自然界中最常见的f区锕系元素之一，在核工业、能源、军工等领域发挥着不可或缺的作用。铀酰（UO22+）是含有铀元素的常见化合物之一。以铀酰为基本结构单元可以组成团簇、二维和三维等多种尺寸的材料。进一步研究表明，一些铀酰团簇具有与碳团簇相似的拓扑结构。基于铀酰团簇与碳团簇的拓扑结构相似性，我们提出类石墨烯二维铀酰材料具有存在的可能。经过研究，我们发现铀酰团簇中的铀酰与配位氢氧根（U-(OH)2-U）结构有助于平面铀酰材料的形成。接着，我们通过全局极小点搜索进一步预测了具有蜂窝状六边形结构的类石墨烯二维铀酰材料。进一步研究表明，在二维铀酰材料中与铀酰配位的双氧基团是超氧O2-，其上面单占的2p??电子形成了一维反铁磁海森堡链。此外，对其能带计算的结果表明，它是具有3.4 eV带隙的半导体。声子谱和第一性原理分子动力学（AIMD）计算表明，这种二维铀酰材料具有很好的动力学和热力学稳定性，有望在实验中进一步合成。最新的研究表明，富勒烯团簇可以聚合形成二维富勒烯材料。我们通过理论计算证实，这种材料中C60分子间键的形成导致其内部碳笼间的pπ*电子可以从孤立C60分子的pπ*反键轨道转移到pσ成键轨道，从而稳定了二维富勒烯结构。此外，我们还发现在其费米能级之上具有s、p和d轨道特征的超原子分子轨道及其产生的近自由电子能带。基于上述二维富勒烯，我们进一步设计了锕系双金属内嵌的二维富勒烯材料。我们发现，U2分子内嵌后，二维富勒烯的稳定性显著增加。此外，声子谱和AIMD模拟计算结果表明这两种材料具有很好的动力学稳定性。接着，我们研究了锕系内嵌二维富勒烯结构中的U-U和Th-Th之间的多重键。结果表明，由于锕系双原子与碳笼之间的转移导致在内嵌的U2二维富勒烯中形成5个单电子键，而在内嵌Th2的二维富勒烯中形成了2个单电子键。
Two-dimensional (2D) materials possess diverse applications across physics, chemistry, and materials science, making it crucial to develop innovative methods for designing, predicting, and synthesizing such materials. As theoretical calculation prediction tools advance, numerous 2D materials composed of s, p, and d-block elements have been predicted to stably exist, with some already successfully synthesized experimentally. However, research on 2D materials containing f-block elements remains scarce. Uranium, a common actinide f-block element in nature, plays a vital role in the nuclear industry, energy production, and military applications. Uranyl (UO22+) is a prevalent uranium-containing compound. Uranyl-based structural units can form clusters, as well as 2D and 3D materials in various dimensions. Studies indicate that some uranyl clusters exhibit topological structures akin to carbon clusters.Drawing on the topological structure similarities between uranyl and carbon clusters, we propose the potential existence of graphene-like 2D uranyl materials. Our research reveals that the uranyl and coordinated hydroxyl (U-(OH)2-U) structures in uranyl clusters contribute to the formation of planar uranyl materials. We subsequently predicted a graphene-like 2D uranyl material with a hexagonal honeycomb structure through a global minimum search. Further investigation shows that the coordinated peroxy groups in 2D uranyl materials are superoxide O2-, and the singly occupied 2pπ* electrons form a one-dimensional antiferromagnetic Heisenberg chain. Additionally, the band structure calculations indicate that it is a semiconductor with a 3.4 eV bandgap. Phonon spectra and ab initio molecular dynamics (AIMD) calculations suggest that this 2D uranyl material exhibits good kinetic and thermodynamic stability, making it a promising candidate for further experimental synthesis.Recent studies have shown that fullerene clusters can aggregate to form 2D fullerene materials. Through theoretical calculations, we confirmed that the formation of C60 intermolecular bonds in this material stabilizes the 2D fullerene structure by transferring the internal carbon cage pπ* electrons from antibonding orbital of the isolated C60 molecule to the pσ bonding orbital. Furthermore, we identified superatomic molecular orbitals with s, p, and d-orbital characteristics above its Fermi level, along with their resulting nearly-free electron bands. Building on this 2D fullerene, we designed 2D actinide-based endohedral metallofullerenes materials. We discovered that upon embedding U2 molecules, the stability of the 2D fullerene significantly increases. Phonon spectra and AIMD simulation results also reveal good kinetic stability for these two materials. We then examined the multiple bonds between U-U and Th-Th in the actinide-embedded 2D fullerene structure. Our findings show that, due to the transfer between actinide dimers and carbon cages, five single-electron bonds form in the embedded U2 2D fullerene, while two single-electron bonds form in the embedded Th2 2D fullerene.
