Carbon nanotube is a one-dimensional quantum material with a special structure (nanometer scale in radial dimension, micron scale in axial dimension, and essentially sealed at both ends of the tube). Carbon nanotubes are mainly composed of carbon atoms arranged in a hexagonal pattern forming coaxial circular tubes with several to tens of layers. The distance between the layers is fixed at about 0.34 nm, and the diameter is generally from 2 to 20 nm. The carbon hexagon can be divided into serrated, armchair and spiral according to its different orientation along the axial direction. The helical carbon nanotubes have chirality, while the sawtooth and armchair carbon nanotubes do not have chirality. Carbon nanotubes, as one-dimensional nanomaterials, are light in weight and perfectly connected in hexagonal structure, and have many unusual mechanical, electrical and chemical properties. In recent years, as the research on carbon nanotubes and nanomaterials has intensified its broad application prospects have been continuously shown.
In the main VMD window, click on "Extensions menu>>Modeling>>Nanotube Builder"
Then a "Carbon Nanostructu..." window will pop up. This window is divided into three sections: ① Topology Building Options; ② Nanotube Building Options; ③ Graphene Sheet Building Options.
If you want to create a boron nitride carbon nanotube, we just need to change the C-C of Material to B-N and click Generate Nanotube, then you can see the B-N nanotube in the OpenGL window.
Then, as in the previous tutorial, change the Drawing Method to CPK in the Graphical Representation window and adjust the parameters of the ball and stick.
If you do not like the color of the atoms, you can click on "Graphics menu>>Colors", select the current coloring method (Name) in the "Color Controls" window, find the N atom and change its color "e.g. 1 red".
The background color can also be modified in the Color Controls window. The specific action is "Dispaly→Background→8 White".
If you do not want to display the axes, you can select "Axes>>Off" in the Display menu.
Find a suitable angle, click "File menu>>Render", click Browse, set the save path and file name (.bmp suffix), and then click Start Rendering. (If you want to export the 3D format, you can Render the current scene using the list of options) Select Wavefront (OBJ and MTL))
As for the type of B-N nanotubes, similar to carbon nanotubes, there are three types: Armchair, Zigzag and Chiral form. When creating them, note that there are two helix indices (n and m, integers).
When m = n, it is Armchair type
Zigzag form when m > n = 0
Chiral form when m > n ≠ 0
The length of the nanotube is controlled by the Nanotube length (nm). The value of n+m is the number of red or blue-green spiral strips shown in the figure when viewed in the direction of the nanotube.
In addition to nanotubes, hexagonal boron nitride in honeycomb form can also be generated in one click.