Theoretical Studies of the Electronic Properties of Ceramic Materials

Abstract

The first-principles orthogonalized linear combination of atomic orbitals (OLCAO) method for electronic structure studies has been applied to a variety of complex inorganic crystals. The theory and the practice of the OLCAO method in the local density approximation are discussed in detail. Recent progress in the study of electronic and optical properties of a large list of ceramic systems are summarized. Eight selected topics on different ceramic crystals focusing on specific points of interest are presented as examples. The materials discussed are AIN, Cu20, p-Si3N4, Y203, LiB305, ferroelectric crystals, Fe-B compounds, and the YBa2Cu307 superconductor. The results include the band structure, density of states, charge density distribution, spin density distribution, effective charges, total energy and totalenergy-derived results, optical absorption, positron annihilation spectra, and more. Extension of the band theoretical approach to the study of other areas of fundamental ceramic science is also discussed. [

Electronic structure and optical conductivities of 20 MAX-phase compounds

“…The electronic structure and optical conductivities of the MAX phases were calculated using the first-principles orthogonalized linear combination of atomic orbitals (OLCAO) method 20 which is based on the local density approximation (LDA) of density functional theory. 21,22 This method has been demonstrated to be highly accurate and efficient when dealing with materials with complex structures for both crystalline [23][24][25][26][27][28][29] and non-crystalline systems [30][31][32][33][34] .…”

Theoretical Investigation of Al K-edge X-ray Absorption Spectra of Al, AlN and Al<SUB>2</SUB>O<SUB>3</SUB>

“…However, most of these methods only provide qualitative agreement with experimental data. Recently, a first-principles band structure calculation using an orthogonalized linear combination of the atomic orbitals (OLCAO) method 14) was successfully used to reproduce the experimental spectral fine structures quantitatively. 15,16) Various Al K-edge XANES spectra of Al compounds have been extensively studied both experimentally and theoretically.…”

Ab initioinvestigation of hydrogen bonding and network structure in a supercooled model of water

“…19 A full basis set of H (1s, 2s, 2p) and O (1s, 2s, 2p , 3s, 3p) was used to obtain the density of states (DOS) and partial DOS (PDOS). For the XANES calculation, the basis was further extended by one more shell of unoccupied atomic orbitals for more accurate determination of higher energy states.…”