Abstract

A first principles local density functional investigation on extended, two-dimensional periodic slab models of the MgO(001) surface is performed, using the linear combination of Gaussian-type orbitals (LCGTO) technique as implemented in the FILMS program package. Stimulated by recent theoretical evidence for a reduced charge separation in MgO(001), a detailed analysis of the charge distribution and its influence on the electrical field above the surface is carried out. Two different methods to quantify the charge separation in the ionic substrate are employed, a local one based on the topological atom approach and a global one derived from the Madelung field of the surface near potential adsorbates. Both procedures lead to a charge separation significantly (10%–20%) below the nominal ionic value of ±2 a.u. A variational atomic orbital analysis is utilized to discuss the origin of the Mg 3s and 3p structures discernible in the crystal orbitals of the MgO slab systems. They are identified as covalent magnesium valence orbital admixtures to the oxygen dominated valence bands in consistence with the reduced charge separation. Their influence on the cohesive energy of crystalline MgO, however, is found to be only 5% (∼0.5 eV).

Keywords

Valence (chemistry)Charge densityIonic bondingAtomic orbitalIonic potentialMaterials scienceCovalent bondChemical physicsPartial chargeMolecular physicsAtomic physicsChemistryIonMoleculePhysics

Affiliated Institutions

Related Publications

<i>A</i> <i>b</i> <i>i</i> <i>n</i> <i>i</i> <i>t</i> <i>i</i> <i>o</i> effective core potentials including relativistic effects. V. SCF calculations with ω–ω coupling including results for Au2+, TlH, PbS, and PbSe

A b initio self-consistent field calculations are reported for a series of diatomic molecules using relativistic effective core potentials (REP) and basis sets appropriate for ω...

1980 The Journal of Chemical Physics 70 citations

Publication Info

Year
1994
Type
article
Volume
100
Issue
9
Pages
6826-6836
Citations
84
Access
Closed

External Links

Social Impact

Social media, news, blog, policy document mentions

Citation Metrics

84
OpenAlex

Cite This

U. Birkenheuer, J. C. Boettger, Notker Rösch (1994). Charge separation and covalent bonding in metal oxide surfaces: A local density functional study on the MgO(001) surface. The Journal of Chemical Physics , 100 (9) , 6826-6836. https://doi.org/10.1063/1.467042

Identifiers

DOI
10.1063/1.467042