Clar covers and Zhang-Zhang polynomials of zigzag and armchair carbon nanotubes (Q6630947)

Using the interface theory of benzenoids and the transfer matrix methodology, the authors derive the compact formulas for the Zhang-Zhang (ZZ) polynomials of two classes of finite open-ended carbon nanotubes: the zigzag nanotubes \((n, 0)\) of length \(d\) and the armchair nanotubes \((n, n)\) of length \(d\). For the zigzag nanotubes, the underlying Clar cover theory is trivial; in contrast, for the armchair nanotubes, the Clar theory is complicated and abundant in results.