论文标题
碳纳米材料中的thor和碳六角形之间的特殊化学键合
Peculiar chemical bonding between thorium and a carbon hexagon in carbon nanomaterials
论文作者
论文摘要
我们探索了th throm原子与新型碳材料中六个碳原子（六碳原子）环的化学键合的异常性质。我们对基于th的金属金属（th@c60，th@c20）和苯和冠状的限制计算，该计算在哈特里 - 福克水平上限制为二阶扰动（MP2）校正（van der waals相互作用），这表明thor at thorium Atom的最佳位置位于I it It ats in e sex中心的最佳位置。对于C60中包装的TH，发现在2.01 A处，而其他局部能量最小值则转移到更大的能量（0.22 eV及更高）。在C60内部，当五个成员碳环（五角大楼）的中心面向1.17 eV处的最高局部最小值。基于我们使用苯和冠状烯对TH的计算，其中TH的全局最小值对应于六边形中心的2.05 A（苯）或2.02 A（Coronene）的位置，我们得出结论，在石墨烯和单壁碳纳米管中可能存在明显的最小值。 TH的基态是单线，其他高自旋状态（三重态和五重奏）的能量更高（> 1.62 eV）。我们讨论碳纳米材料的潜在用途，其第229同位素具有光学范围的核转变，以实现计量范围。
We explore an unusual nature of chemical bonding of the thorium atom with a ring of six carbon atoms (hexagon) in novel carbon materials. Our ab initio calculations of Th-based metallofullerenes (Th@C60, Th@C20) and Th bound to benzene or coronene at the Hartree-Fock level with the second order perturbation (MP2) correction accounting for the van der Waals interactions, demonstrate that the optimal position of the thorium atom is where it faces the center of a hexagon and is located at a distance of 2.01-2.07 A from the center. For Th encapsulated in C60 it is found at 2.01 A, whereas the other local energy minima are shifted to larger energies (0.22 eV and higher). Inside C60 the highest local minimum at 1.17 eV is observed when Th faces the center of the five member carbon ring (pentagon). Based on our calculations for Th with benzene and coronene where the global minimum for Th corresponds to its position at 2.05 A (benzene) or 2.02 A (coronene) from the hexagon center, we conclude that a well pronounced minimum is likely to present in graphene and in a single wall carbon nanotube. The ground state of Th is singlet, other high spin states (triplet and quintet) lie higher in energy (> 1.62 eV). We discuss a potential use of the carbon nanomaterials with the 229Th isotope having the nuclear transition of the optical range, for metrological purposes.
