Ab initio study of the elastic properties of single-walled carbon nanotubes and graphene

The first all-electron ab initio study of Youngʹs modulus and Poisson ratio for a number of closed single-walled nanotubes is presented. At the Hartree–Fock 6-31G∗ level, the results obtained compare well with experimental as well as previous theoretical studies, predicting a Youngʹs modulus higher than 1 TPa. The calculated Youngʹs modulus for a graphene layer is found to be smaller than for its (5,5)-nanotube counterpart.