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Author Ching, W. Y. ♦ Xu, Yong-Nian ♦ Brickeen, B. K.
Sponsorship (US)
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Publisher The American Physical Society
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ ALUMINIUM ♦ ATOMS ♦ BONDING ♦ CHARGE DISTRIBUTION ♦ EFFECTIVE CHARGE ♦ ELECTRONIC STRUCTURE ♦ GARNETS ♦ GEOMETRY ♦ IONIC CRYSTALS ♦ LASERS ♦ SAPPHIRE ♦ YTTRIUM
Abstract The ground-state electronic structure and bonding of two important laser crystals, BeAl{sub 2}O{sub 4} and LiYF{sub 4}, were calculated using a first-principles method based the local approximation of the density-functional theory. The results were compared with similar calculations on several other laser crystals including yttrium aluminum garnet (Y{sub 3}Al{sub 5}O{sub 12}). The geometry of each crystal was optimized first with all internal parameters relaxed. The bulk moduli B were obtained by fitting the calculated total energies at different volumes to the Murnaghan equation of state. It was found that LiYF{sub 4} (B=90.0GPa) is much softer than BeAl{sub 2}O{sub 4} (B=217.3GPa). In BeAl{sub 2}O{sub 4}, Be and Al atoms have very similar local electronic structure and the crystal resembles that of {alpha}-Al{sub 2}O{sub 3} (sapphire). LiYF{sub 4} is a highly ionic crystal while BeAl{sub 2}O{sub 4} has a significant amount of covalent mixing. The density of states, their atomic and orbital decompositions, the effective charges, the bond order, and the charge distributions in these two crystals are presented and contrasted.
ISSN 01631829
Educational Use Research
Learning Resource Type Article
Publisher Date 2001-03-15
Publisher Place United States
Journal Physical Review B
Volume Number 63
Issue Number 11


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