The structure of high pressure Ca(OD)(2) II from powder neutron diffraction: Relationship to the ZrO2 and EuI2 structures

被引：14

作者：

Leinenweber, K ^{[1
]}

Partin, DE ^{[1
]}

Schuelke, U ^{[1
]}

OKeeffe, M ^{[1
]}

VonDreele, RB ^{[1
]}

机构：

[1] LOS ALAMOS NATL LAB,MLNSCE,LOS ALAMOS,NM 87545

来源：

JOURNAL OF SOLID STATE CHEMISTRY | 1997年 / 132卷 / 02期

基金：

美国国家科学基金会;

关键词：

D O I：

10.1006/jssc.1997.7439

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

The ''unquenchable'' high pressure form of Ca(OD)(2) [Ca(OH)(2)II] has been synthesized at 9 GPa and 400 degrees C and recovered to ambient pressure at cryogenic temperatures. The structure was determined from powder neutron diffraction data using the Rietveld technique, The symmetry is monoclinic P2(1)/c with a = 5.3979(4) Angstrom, b = 6.0931(4) Angstrom, c = 5.9852(4) Angstrom, beta = 103.581(6)degrees, Z = 4 at 1 atm and 11 K. R-wp = 2.8%, R-p = 1.9%, reduced chi(2) = 6.6. for 117 variables. The calcium and oxygen substructure is intermediate between that in alpha-PbO2 and that in fluorite; it was previously described as isostructural with bad-deleyite (ZrO2), but it is more accurately described as isostructural with EuI2. This structure is distinguished by the presence of a 3(6) anion net parallel to (100). Only one of the two kinds of D atoms in the structure shows appreciable hydrogen bonding to O, with a second neighbor D ... O distance of 1.91 Angstrom, and an O-D ... O angle of 153.2 degrees; the other D atom has 3 second-neighbor oxygens near 2.6 Angstrom away. (C) 1997 Academic Press.

引用

页码：267 / 273

页数：7

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