Atomic structure and doping of microtubules

Abstract

The atomic and electronic structures of microtubules of graphitic carbon have been investigated by ab initio molecular dynamics. Fully optimized atomic structures of two microtubules, a reflection symmetric and a chiral, are found to differ little from their ideal, graphite-derived geometries. Both are semiconductors with direct band gaps at the Γ point and along the Δ direction, respectively. It is shown by direct calculations in large supercells that substitutional N and B dope microtubules n and p type.