Structures and Stabilities of Doubly-charged (MgO)nMg2+ (n=1-29) Cluster Ions
Abstract
Ab initio perturbed ion plus polarization calculations are reported for doubly-charged nonstoichiometric (MgO)nMg2+ (n=1-29) cluster ions. We consider a large number of isomers with full relaxations of the geometries, and add the correlation correction to the Hartree-Fock energies for all cluster sizes. The polarization contribution is included at a semiempirical level also for all cluster sizes. Comparison is made with theoretical results for neutral (MgO)n clusters and singly-charged alkali-halide cluster ions. Our method is also compared to phenomenological pair potential models in order to asses their reliability for calculations on small ionic systems. The large coordination-dependent polarizabilities of oxide anions favor the formation of surface sites, and thus bulklike structures begin to dominate only after n=24. The relative stabilities of the cluster ions against evaporation of a MgO molecule show variations that are in excellent agreement with the experimental abundance spectra.
Keywords
Cite
@article{arxiv.physics/9808036,
title = {Structures and Stabilities of Doubly-charged (MgO)nMg2+ (n=1-29) Cluster Ions},
author = {Andres Aguado and Francisco Lopez-Gejo and Jose M. Lopez},
journal= {arXiv preprint arXiv:physics/9808036},
year = {2009}
}
Comments
Final version accepted in Journal of Chemical Physics; 8 pages plus 8 figures (6 GIFs and 2 PSs). The main difference with respect to the original submission is the inclusion of coordination-dependent polarizabilities for oxide anions. That results in substantial changes in the results