Stability of Small MgO Nanotube Clusters:  Predictions of a Transferable Ionic Potential Model

The recently introduced compressible-ion interaction model (CIM) is extended to allow for coordination number-dependent oxide polarizabilities. The variable polarizability is parametrized from existing Hartree−Fock calculations. The resulting potential is used to examine small (MgO) n clusters in both their relaxed and unrelaxed (more symmetrical) structures. The results are compared to experimental results and both Hartree−Fock and density functional theory calculations. Comparison with alkali halide clusters is also made. The potential is found to be transferable over a wide range of ionic environments, spanning gas-phase clusters and the bulk phase. MgO nanotubes are found to be stable for small clusters of less than 30 molecules.