Book contents
- Frontmatter
- Contents
- Preface
- List of Contributors
- Part I Introduction
- Part II Advances in Theoretical and Experimental Techniques
- Part III New Findings in Oxides and Silicates
- Part IV Transformations in Silica
- Part V Novel Structures and Materials
- Chapter 5.1 Opportunities in the Diversity of Crystal Structures – A View from Condensed-Matter Physics
- Chapter 5.2 Theoretical Search for New Materials – Low-Temperature Compression of Graphitic Layered Materials
- Chapter 5.3 H…H Interactions and Order–Disorder at High Pressure in Layered Hydroxides and Dense Hydrous Phases
- Part VI Melts and Crystal–Melt Interactions
- Subject Index
- Materials Formula Index
- Index of Contributors
Chapter 5.3 - H…H Interactions and Order–Disorder at High Pressure in Layered Hydroxides and Dense Hydrous Phases
Published online by Cambridge University Press: 05 November 2011
- Frontmatter
- Contents
- Preface
- List of Contributors
- Part I Introduction
- Part II Advances in Theoretical and Experimental Techniques
- Part III New Findings in Oxides and Silicates
- Part IV Transformations in Silica
- Part V Novel Structures and Materials
- Chapter 5.1 Opportunities in the Diversity of Crystal Structures – A View from Condensed-Matter Physics
- Chapter 5.2 Theoretical Search for New Materials – Low-Temperature Compression of Graphitic Layered Materials
- Chapter 5.3 H…H Interactions and Order–Disorder at High Pressure in Layered Hydroxides and Dense Hydrous Phases
- Part VI Melts and Crystal–Melt Interactions
- Subject Index
- Materials Formula Index
- Index of Contributors
Summary
Observations of order–disorder phenomena at high pressure in hydrous phases are reinterpreted with the results of Rietveld analysis and neutron-diffraction data. The reported partial amorphization of the hydrogen sublattice in β-Co(OD)2 at 11.2 GPa was not confirmed in powder-diffraction data collected with the Paris-Edinburgh cell to 15.5 GPa. The diffraction data, and perhaps the spectroscopic data on which the observations of amorphization are based, are consistent with an increase in the H…H repulsion with pressure. The structural consequences of competition between H…H repulsion and H-bond (O—H…O) formation is observed in the M(OH)2 compounds in general. It is also observed in the dense high-pressure phases recovered from high-pressure synthetic experiments.
Introduction
The hydrogen bond (X—H… Y) is one of the most studied bond geometries in the mineralogical, biological, and solid-state organic chemical communities [1, 2]. For nonmineral and mineral structures alike, the published literature, consisting mainly of crystal-structure determinations at ambient pressure, provides a means to study the bond as donor (X) and acceptor (Y) vary over a variety of structures and chemistries [3, 4]. The secondary environment, however, is important in considering the effects of structure on H-bond geometry [5]; in many cases gross changes in this environment from one structure type to the next make it difficult to separate the effects of the relatively weak H bonding from the steric effects because of the framework making up the remainder of the structure [5].
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- Physics Meets MineralogyCondensed Matter Physics in the Geosciences, pp. 308 - 322Publisher: Cambridge University PressPrint publication year: 2000