Acta Cryst. (1999). B55, 712-720 [doi:10.1107/S010876819900395X]
Abstract: Structure factors for rubidium titanyl arsenate, RbTiOAsO4, were measured with Mo K![[alpha]](/logos/entities/alpha_rmgif.gif)
radiation (![[bold lambda]](/logos/entities/lambda_bdgif.gif)
= 0.71069 Å) at 9.6 and 295 K. The data show that there is no phase transition between room temperature and 9.6 K. The space group is Pna21. Unit-cell parameters are a = 13.218 (1), b = 6.6500 (9) and c = 10.761 (1) Å at 9.6 K, and a = 13.261 (2), b = 6.6791 (8) and c = 10.769 (1) Å at 295 K. As the temperature was lowered from 295 to 9.6 K the Rb atoms moved along the c axis in the direction of the polarization vector, while no significant change was noted for the Ti-O-As network. Strong accumulation and polarization of the difference electron density (![[Delta]](/logos/entities/Delta_rmgif.gif)
![[bold rho]](/logos/entities/rho_bdgif.gif)
) in exceptionally short covalent Ti-O bonds alternates with the depleted density in long Ti-O bonds. The near the Ti atoms is polarized and aligned in the negative c direction in accordance with the ferroelectric properties of this material. However, the electron density near the Rb atoms is depleted in this direction and the excess is moved further away from the nuclei along the c vector.
Online 1 October 1999
 |   Structure factor file (CIF format) (218.9 kbytes) |
| Structure factor file (CIF format) (220.4 kbytes) |
To open or display or play some files, you may need to set your browser up to use the appropriate software. See the full list of file types for an explanation of the different file types and their related mime types and, where available links to sites from where the appropriate software may be obtained.
The download button will force most browsers to prompt for a file name to store the data on your hard disk.
Where possible, images are represented by thumbnails.
Copyright © International Union of Crystallography
IUCr Webmaster