How to calculate Young's modulus of CNT

[Feng]

Hi all,

Any suggestions how to use ATK to calculate the Young's modulus of CNT? Thank you.

[zh]

A simple way:

1. Calculate the total energies(E) of CNT as a function of the periodic length (l);
2. According to the relationship between the Young's modulus and the total energy ([tex]Y \propto \partial^2E/\partial l^2[/tex]), do a quadratic polynomial fit of the data obtained in the 1st step.
[tex]Y= \frac{1}{l_{eq}A}\frac{d^2E}{dl^2} [/tex], where [tex]l_{eq}[/tex] is the periodic length of CNT at equilibrium state, and [tex]A[/tex] is the the area of cross section of CNT.

[Feng]

Thank you very much. I will try it.

[Anders Blom]

One thing you will note when checking the literature on this topic is that the definition of the "cross section area" is rather arbitrary for a nanotube, leading to results that differ quite a lot.