Next Article in Journal
Hexaethylguanidinium Salts
Previous Article in Journal
Phase Energy Determined from Stress and Electric-Field-Induced Phase Transformations in [011]C Cut 0.24PIN-PMN-PT Single Crystals
Article Menu

Export Article

Open AccessArticle
Crystals 2014, 4(3), 390-403; doi:10.3390/cryst4030390

Modeling the Shape of Ions in Pyrite-Type Crystals

IHP, Im Technologiepark 25, 15236 Frankfurt (Oder), Germany
Received: 13 April 2014 / Revised: 22 August 2014 / Accepted: 26 August 2014 / Published: 3 September 2014
View Full-Text   |   Download PDF [596 KB, uploaded 3 September 2014]   |  

Abstract

The geometrical shape of ions in crystals and the concept of ionic radii are re-considered. The re-investigation is motivated by the fact that a spherical modelling is justified for p valence shell ions on cubic lattice sites only. For the majority of point groups, however, the ionic radius must be assumed to be an anisotropic quantity. An appropriate modelling of p valence ions then has to be performed by ellipsoids. The approach is tested for pyrite-structured dichalcogenides MX2, with chalcogen ions X = O, S, Se and Te. The latter are found to exhibit the shape of ellipsoids being compressed along the <111> symmetry axes, with two radii r|| and r describing their spatial extension. Based on this ansatz, accurate interatomic MX distances can be derived and a consistent geometrical model emerges for pyrite-structured compounds. Remarkably, the volumes of chalcogen ions are found to vary only little in different MX2 compounds, suggesting the ionic volume rather than the ionic radius to behave as a crystal-chemical constant. View Full-Text
Keywords: ionic radius; ionic shape; bonding distance; ionic volume; pyrite-type compounds; di-chalcogenides; di-oxides; di-sulfides; di-selenides; di-tellurides ionic radius; ionic shape; bonding distance; ionic volume; pyrite-type compounds; di-chalcogenides; di-oxides; di-sulfides; di-selenides; di-tellurides
Figures

This is an open access article distributed under the Creative Commons Attribution License (CC BY 3.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Birkholz, M. Modeling the Shape of Ions in Pyrite-Type Crystals. Crystals 2014, 4, 390-403.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Crystals EISSN 2073-4352 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top