CaSO4 and Its Pressure-Induced Phase Transitions. A Density Functional Theory Study

Theoretical investigations concerning possible calcium sulfate, CaSO4, high-pressure polymorphs have been carried out. Total-energy calculations and geometry optimizations have been performed by using density functional theory at the B3LYP level for all crystal structures considered. The following s...

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Bibliographic Details
Published in:Inorganic chemistry 2012-02, Vol.51 (3), p.1751-1759
Main Authors: Gracia, Lourdes, Beltrán, Armando, Errandonea, Daniel, Andrés, Juan
Format: Article
Language:English
Online Access:Get full text
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Summary:Theoretical investigations concerning possible calcium sulfate, CaSO4, high-pressure polymorphs have been carried out. Total-energy calculations and geometry optimizations have been performed by using density functional theory at the B3LYP level for all crystal structures considered. The following sequence of pressure-driven structural transitions has been found: anhydrite, Cmcm (in parentheses the transition pressure) → monazite-type, P21/n (5 GPa) → barite-type, Pnma (8 GPa), and scheelite-type, I41/a (8 GPa). The equation of state of the different polymorphs is determined, while their corresponding vibrational properties have been calculated and compared with previous theoretical results and experimental data.
ISSN:0020-1669
1520-510X
DOI:10.1021/ic202056b