Ab initio calculations on (OH)4) defects in α-quartz

Saved in:
Authors:Lin, J. S.; Payne, M. C.; Heine, V.; McConnell, J. D. C.
Author Affiliations:Primary:
University of Cambridge, Cavendish Laboratory, Cambridge, United Kingdom
Volume Title:Physics and Chemistry of Minerals
Source:Physics and Chemistry of Minerals, 21(3), p.150-155. Publisher: Springer-Verlag, Berlin-New York, Federal Republic of Germany. ISSN: 0342-1791
Publication Date:1994
Note:In English. 21 refs.; illus., incl. 4 tables
Summary:Ab Initio total energy calculations based on a new optimized oxygen pseudopotential have been used to study the structures and relative energies of α-quartz, a partly (OH)4 substituted version of the α-quartz structure, and interstital water molecules in α-quartz. Hydrogen bonds formed from two hydroxyl groups of the (OH)4 defects in the substituted α-quartz structure promote a stable structure for the defect α-quartz at low T. Comparable ab initio calculation of the energy of the interstitial water molecule in the quartz structure indicates that, energetically, the (OH)4 defect is likely to be strongly favoured as a mode for the incorporation of water. Ab initio stress calculations confirm that the (OH)4 defect in quartz has a large associated stress field which is likely to lead to segregation of these defects on supersaturation in wet quartz. The calculations indicate that segregation should occur in the plane (10<[dollar]E 1 back 40 up 40 ->0) of the α-quartz structure. [Authors' abstract] - S. [A.T.R.]
Subjects:Alpha quartz; Crystal structure; Defects; Framework silicates; Hydroxyl ion; Low temperature; Quartz; Silica minerals; Silicates; Temperature; Thermodynamic properties; Water; Weathering
Abstract Numbers:96M/1548
Record ID:1995032386
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom
Tags: Add Tag
No Tags, Be the first to tag this record!
Be the first to leave a comment!
You must be logged in first