有限长扶手椅形单壁碳纳米管分子静电势的理论研究

Theoretical study of the molecular electrostatic potential of finite armchair single-wall carbon nanotubes

在混合密度泛函B3LYP理论下,用3-21G基函数对有限长扶手椅形单壁碳纳米管(4,4)(、5,5)和(6,6)的构型进行优化和分子静电势计算.结果表明:除近核区域为正常的正电势外,碳纳米管结构模型的管内和管外为负电势区域;在碳纳米管结构模型的管内,管心处均出现负电势的最小值,且负电势的绝对值随着碳纳米管的曲率降低而增大,管心轴线上静电势的变化随碳纳米管的曲率降低而减少,带电粒子流比较容易通过纳米管.

The optimized configurations and the molecular electrostatic potentials have been obtained based on the density-functional theory using 3-21G basis set for finite armchair single-walled carbon nanotubes of(4,4)、(5,5)and(6,6).The calculated results show that the electrostatic potentials of most areas are negative except the area nearby carbon nucleus.The potential minimum inside the tube occurs at the tube core,the absolute value of negative potential in the regions of the cube core is much bigger,which becomes larger with the decreasing of curvature.The smaller variation of electrostatic potentials is in the direction of the tube axis and the tube with a smaller curvature has a smaller variation of electrostatic potentials.The electrons can pass through the tube easily.