半经验方法用于不同尺寸单壁纳米管的稳定性研究(英文)  

Semiempirical study on the stability of single-walled carbon nanotubes with different sizes

作　　者：林翼[1] 蔡文生[1,2] 邵学广[2] 

机构地区：[1]中国科学技术大学化学系,安徽合肥230026 [2]南开大学化学系

出　　处：《计算机与应用化学》2007年第1期97-102,共6页Computers and Applied Chemistry

基　　金：国家自然基金项目(20573102)~~

摘　　要：利用PM3方法对不同直径(1．6-40．7A)、长度(1．2-20．9A)和类型(扶手椅型、锯齿型及手性型)的开口单壁纳米管的热力学稳定性进行了系统研究。结果表明:直径大于10 A的比较稳定;扶手椅型比其他类型的稳定;直径相同时,长度长的比短的稳定;原子数相同时,具有适当长径比的结构较为稳定;扶手椅型的电子结构主要取决于纳米管的长度,而锯齿型则取决于管的直径。所得结论与其它量化计算结果以及实验观测相符合。Using PM3 semiempirical method, we have systematically studied the stability of open-ended single-walled carbon nanotubes with different diameters （from 1.6 to 40.7A）, lengths （from 1.2 to 20.9A） and chiralities （containing armchair, zig-zag and chiral） by comparing their energies and electronic structures. The calculated results show that the nanotubes with diameter larger than 10A would be thermodynamically stable, and the smallest open-ended single-walled carbon nanotubes are armchair （2, 2） and zig-zag （4, 0）. Armchair nanotubes are more stable than other chiralities, and the longer nanotubes with ends open are thermodynamically more stable. The electronic structures of armchair tubes mainly depend on the tubular length, while the tubular diameter has more influences on zig-zag tubes. Properly slim nanotubes are energetically more stable than fiat ones. These conclusions are in good agreement with the published results by quantum-chemical methods and experimental observations.

关 键 词：碳纳米管 PM3方法 稳定性 电子结构 模拟 

分 类 号：O64[理学—物理化学] TB322[理学—化学]