Some size-dependent electronic properties in charged MgO clusters
Laboratoire de Physique des Solides, Université Paris-Sud, Bâtiment 510, 91405 Orsay, France
Corresponding author: a email@example.com
Revised: 17 March 2003
Published online: 12 August 2003
Starting from two cubic pieces of a MgO crystal (() and ()), both containing a central oxygen atom, two clusters are simulated with the help of a DFT-LDA method. These clusters are charged in order to be equivalent to pieces of a neutral crystal. In each cluster, a neutral vacancy analogous to a F center is created by removing the central oxygen atom. Then, F+ and F++ centers are simulated by removing one and two electrons. The main differences and similarities between the two sizes of clusters are studied: geometries, Mulliken charges, electronic distributions, gaps, ionisation potentials. An important result is that in any case, when a F center is simulated, the vacancy does not accept more than about one electron, the second one being spread in the rest of the cluster.
PACS: 31.15.Ar – Ab initio calculations / 36.40.Wa – Charged clusters / 61.72.Ji – Point defects (vacancies, interstitials, color centers, etc.) and defect clusters
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2003