Computations of the quadrupole coupling constants in aluminum doped boron nitride nanotubes

We performed a computational study to calculate the quadrupole coupling constants (CQ) in the aluminum doped (Al-doped) boron nitride nanotube (BNNT) based on the density functional theory (DFT). The Al-doped forms of representative (6,0) zigzag and (4,4) armchair models of BNNTs are considered in this study. Comparison with the available data on the pristine BNNTs reveals the influence of Al-doping on the CQ parameters of 11B and 14N atoms in the Al-doped structures. For most lattice sites, the magnitude of influence on the CQ parameters of the zigzag model is larger than that of the armchair model. Similar values of the CQ parameters of 27Al atoms are obtained for the armchair and zigzag BNNTs when the same element is replaced with Al, but the CQ parameter is larger for Al when it forms an Al-B bond than when it forms an Al-N bond.