Van der Waals interactions between two parallel infinitely long single-walled nanotubes

The potential energies of van der Waals (VDW) interactions between two parallel, infinitely long and perfect SWNTs with identical, and different sizes were studied based on the continuum Lennard–Jones model. The conclusion of Girifalco’s work on (n, n) SWNTs that the potentials of SWNT–SWNT fell on a single curve, is also applicable to SWNTs with different sizes. We further obtained the corresponding constants of the well depth |ϕ0| and equilibrium VDW gap g0 for SWNTs with a radius from 2 to 25 Å.