Size Dependent Structural and Electronic Properties of MgO Nanotube Clusters

MgO nanotube clusters which cross sections are composed of two-, three-, four-, and five-membered rings are constructed and Studied by the density functional theory at B3LYP/6-31G(d) level. The variations of bond length present anisotropic effect. Three-membered ring nanotube Cluster is the most stable tube among these MgO isomers. Mixed covalent and ionic bonding always exists in MgO nanotube clusters. With increasing length of MgO nanotube clusters, the averaged atomic charge increases, and converge to 1.227; the s-p separation of O bands decreases; whereas energy gap nearby frontier orbitals present dramatic difference corresponding to various structure family. It is possible that MgO nanotube clusters show electronic properties of semiconductor. An interpretation for MgO nanotube Clusters fabricated by simply thermal methods is proposed. The structural and electronic properties of MgO nanotube clusters are discussed systematically in details. (C) 2008 Wiley Periodicals, Inc. Int J Quantum Chem 109: 349-356, 2009