Publication

Formation energy of threefold coordinated oxygen in SiO2 systems

Alfredo Pasquarello
2000
Journal Articles

Abstract

Using density functional calculations in the generalized gradient approximation, the excitation energy for the formation of a threefold coordinated oxygen atom is evaluated. The bistable E-1' defect of alpha-quartz in the neutral charge state is used as a model system. The puckered configuration which shows a threefold coordinated oxygen center together with a doubly occupied silicon dangling bond is found to be at 2.7 eV higher energy than the Si-Si dimer configuration.

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Alfredo Pasquarello
2000
Journal Articles

Abstract

Official source

Related concepts (25)

Crystal structure

In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions, or molecules in a crystalline material. Ordered structures occur from the intrinsic nature of the constituent particles to form symmetric patterns that repeat along the principal directions of three-dimensional space in matter. The smallest group of particles in the material that constitutes this repeating pattern is the unit cell of the structure.

Density functional theory

Density-functional theory (DFT) is a computational quantum mechanical modelling method used in physics, chemistry and materials science to investigate the electronic structure (or nuclear structure) (principally the ground state) of many-body systems, in particular atoms, molecules, and the condensed phases. Using this theory, the properties of a many-electron system can be determined by using functionals, i.e. functions of another function. In the case of DFT, these are functionals of the spatially dependent electron density.

Local-density approximation

Local-density approximations (LDA) are a class of approximations to the exchange–correlation (XC) energy functional in density functional theory (DFT) that depend solely upon the value of the electronic density at each point in space (and not, for example, derivatives of the density or the Kohn–Sham orbitals). Many approaches can yield local approximations to the XC energy. However, overwhelmingly successful local approximations are those that have been derived from the homogeneous electron gas (HEG) model.

Related publications (3)

Formation energy of threefold coordinated oxygen in SiO2 systems

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First principles investigation of defects at interfaces between silicon and amorphous high-kappa oxides

Structure and hyperfine parameters of E'(1) centers in a-quartz and in vitreous SiO2

The torsional potential of perfluoro n-alkanes: a density functional study