State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, People's Republic of China.
J Phys Condens Matter. 2013 Feb 13;25(6):065402. doi: 10.1088/0953-8984/25/6/065402. Epub 2013 Jan 18.
We provide a systematic analytical method for preferable orientation calculations of spherical fullerenes in single-walled boron nitride nanotubes. Based on the reaction energy calculations, both the minimum entering radii and the energetically favorable radii for encapsulating C(60), C(80) and C(180) molecules in boron nitride nanotubes have been proposed. The van der Waals energy as a function of the various orientations of the encapsulated fullerene molecule is shown by a potential contour map, from which we find that the low-energy state appears in the symmetry axis orientation of the encapsulated fullerene molecules with a different size. We thus propose a new systematic analytical method for optimal orientation predictions of spherical fullerenes in the confinement condition, which is based on the symmetry axis but not the method proposed in previous literature, such as using pentagons, double-bonds, and hexagons to analyze the preferable orientation of confined C(60). Our results show that the C(60) molecule in boron nitride nanotubes exhibits three lowest energy states corresponding to the five-, two- and three-fold axis orientations in three radii intervals, while only two preferable orientations-the five- and three-fold axis orientations have been observed for encapsulated C(80) and C(180) molecules.
我们提供了一种系统的分析方法，用于计算球形富勒烯在单壁氮化硼纳米管中的优选取向。基于反应能计算，提出了 C(60)、C(80)和 C(180)分子在氮化硼纳米管中包封的最小进入半径和能量有利半径。范德华能作为包封富勒烯分子各种取向的函数，通过势能等高线图显示，从中我们发现，低能态出现在不同尺寸的包封富勒烯分子的对称轴取向中。因此，我们提出了一种新的系统分析方法，用于预测在约束条件下球形富勒烯的最佳取向，该方法基于对称轴，而不是以前文献中提出的方法，例如使用五边形、双键和六边形来分析受限 C(60)的优选取向。我们的结果表明，氮化硼纳米管中的 C(60)分子在三个半径间隔内呈现出对应于五重、二重和三重轴取向的三个最低能量状态，而对于包封的 C(80)和 C(180)分子，仅观察到两个优选取向——五重和三重轴取向。
