Effect of elliptical deformation on molecular polarizabilities of model carbon nanotubes from atomic increments

The interacting induced dipole polarization model implemented in our program POLAR is used for the calculation of the dipole-dipole polarizability alpha. The method is tested with single-wall carbon nanotube models as a function of nanotube radius and elliptical deformation. The results for polarizability follow the same trend as reference calculations performed with our version of the program PAPID. For the zigzag tubes, the polarizability is found to follow a remarkably simple law, that is, it varies as the inverse of the radius. A dramatic effect is also found with elliptical deformation. It is found that the polarizability and related properties can be modified continuously and reversibly by the external radial deformation. These results suggest an interesting technology in which mechanical deformation can control chemical properties of the carbon nanotubes. POLAR calculations differentiate more effectively than PAPID computations among single-wall nanotube models with increasing radial deformation. Different effective polarizabilities are calculated for the atoms at the highest and lowest curvature sites. POLAR calculations discriminate more efficiently than PAPID computations between the effective polarizabilities of the highest and lowest curvature sites. This remarkable and significant tunable polarizability can have important implications for metal coverage of metals on nanotubes and selective adsorption and desorption of foreign atoms and molecules on nanotubes and can lead to a wide variety of technological applications, such as catalysts, hydrogen storage, magnetic tubes, etc.