Displacement energies for nanorods

The geometries have been optimized and harmonic frequencies for three small hydrocarbon rods. The two lowest unique frequencies correspond to a torsion and a bend of the rods. The energy to bend or twist the rods has been computed by adding a fraction of the normal coordinate corresponding to these two modes to the equilibrium geometry. The density functional theory (using B3LYP) and Hartree-Fock (HF) results are very similar for all properties considered.