Related Experiment Video
Updated: May 7, 2026
11:27
X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050
Published on: May 13, 2020
Tolerance factor for pyrochlores and related structures
R Mouta1, R X Silva, C W A Paschoal
1Departamento de Física, CCET, Universidade Federal do Maranhão, 65085-580, São Luís - MA, Brazil.
Summary
A new empirical tolerance factor for pyrochlore structure compounds is proposed. This factor aids in predicting compound properties and defining their structure stability fields without needing direct structural data.
Area of Science:
- Materials Science
- Solid State Chemistry
- Crystallography
Background:
- Compounds with pyrochlore structure are crucial in various applications.
- Predicting the stability and properties of pyrochlore compounds is essential for material design.
- Existing tolerance factors often rely heavily on specific structural data, limiting predictive power.
Purpose of the Study:
- To propose a novel empirical tolerance factor for pyrochlore structure compounds.
- To develop a predictive tool for pyrochlore properties independent of detailed structural data.
- To establish a reliable structure stability field for pyrochlore formation.
Main Methods:
- Analysis of existing experimental structural data for pyrochlore compounds.
- Development of a new empirical formula for the tolerance factor.
- Validation of the proposed tolerance factor against known pyrochlore structures and properties.
Main Results:
- A new empirical tolerance factor for pyrochlore compounds has been successfully proposed.
- The new tolerance factor allows for direct prediction of certain compound properties.
- The proposed factor effectively defines a good structure stability field for pyrochlore formation.
Conclusions:
- The newly proposed empirical tolerance factor offers a simplified yet effective method for understanding pyrochlore compounds.
- This factor enhances the ability to predict properties and stability, facilitating the discovery of new materials.
- The independence from detailed structural data makes this a versatile tool in materials science research.
Related Concept Videos
01:29Diversity of Archaea IV
Hyperthermophilic archaea are a group of extremophiles thriving at temperatures above 80°C, often in hydrothermal vents and volcanic soils where conditions surpass the boiling point of water. At such temperatures, proteins, membranes, and DNA in most organisms degrade, but hyperthermophiles have evolved remarkable adaptations to maintain stability and function.Unique Cellular FeaturesHyperthermophilic membranes are composed of a monolayer of biphytanyl tetraether lipids, which resist thermal...
01:27Diversity of Archaea III
Crenarchaeota, a prominent phylum of Archaea, is remarkable for its ability to thrive in extreme environments characterized by high temperatures and acidity. These microorganisms inhabit sulfuric hot springs, volcanic systems, and submarine hydrothermal vents, where temperatures often exceed 100°C. The unique adaptations of Crenarchaeota not only allow survival under such extreme conditions but also provide insights into the mechanisms of life in primordial Earth-like environments.Morphological...
01:30Diversity of Archaea I
Archaea, a domain of single-celled microorganisms, are classified into five major phyla based on genetic and biochemical characteristics: Euryarchaeota, Crenarchaeota, Thaumarchaeota, Korarchaeota, and Nanoarchaeota. Among these, the phylum Euryarchaeota is notable for its remarkable diversity in morphology, metabolism, and ecological adaptations.Morphological and Metabolic DiversityMembers of Euryarchaeota exhibit a variety of cellular shapes, including rods and cocci. Their metabolic pathways...
01:16Cycloaddition Reactions: MO Requirements for Thermal Activation
Thermal cycloadditions are reactions where the source of activation energy needed to initiate the reaction is provided in the form of heat. A typical example of a thermally-allowed cycloaddition is the Diels–Alder reaction, which is a [4 + 2] cycloaddition. In contrast, a [2 + 2] cycloaddition is thermally forbidden.
02:36Acidity and Basicity of Alcohols and Phenols
Like water, alcohols are weak acids and bases. This is attributed to the polarization of the O–H bond making the hydrogen partially positive. Moreover, the electron pairs on the oxygen atom of alcohol make it both basic and nucleophilic. Protonation of an alcohol converts hydroxide, a poor leaving group, into water—a good one. The two acid–base equilibria corresponding to ethanol are depicted below.
01:07Radicals: Electronic Structure and Geometry
This lesson delves into the geometry of a radical, which is influenced by the electronic structure of the molecule. The principle is similar to that of a lone pair, where the unpaired electron influences the geometry at the radical center.
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...