The electronic structure and dielectric screening of finite-length armchair carbon nanotubes are studied with both tight-binding and ab initio methods. Good agreement is found in the band gap oscillation patterns and dielectric constants, which validates the tight-binding method as a reliable and fast approach to describe the screening effect of carbon nanotubes. For an illustration, our method is applied to a system consisting of a short (6,6) nanotube filled with six water molecules. Substantial screening of the water dipoles through the nanotube is observed. This polarization effect should have an important influence on the permeation of water and other biomolecules inside carbon nanotubes.

中文翻译：

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有限长度扶手椅碳纳米管内水偶极子的筛选。


采用紧束缚法和从头算法研究了有限长度扶手椅碳纳米管的电子结构和介电屏蔽。带隙振荡模式和介电常数具有良好的一致性，这验证了紧束缚方法是描述碳纳米管屏蔽效应的可靠且快速的方法。作为说明，我们的方法应用于由充满六个水分子的短 (6,6) 纳米管组成的系统。观察到水偶极子通过纳米管的大量屏蔽。这种极化效应应该对碳纳米管内水和其他生物分子的渗透产生重要影响。