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Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Molecular crystal global phase diagrams. III. Sufficient parameter space determination
J Brandon Keith1, Richard B McClurg
1Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA. jbrkeith@gmail.com
Acta Crystallographica. Section A, Foundations of Crystallography
|December 24, 2009
Summary
This study develops a method to determine the necessary parameters for global phase diagrams (GPDs) of molecular crystals. It found 15 parameters are sufficient to represent crystal structures, differing from previous suggestions of thousands.
Area of Science:
- Crystallography
- Materials Science
- Computational Chemistry
Background:
- Global Phase Diagrams (GPDs) visualize crystal structure possibilities based on molecular interactions.
- Previous work established GPD construction for tetrahedral molecules but lacked parameter space specification.
- Understanding parameter space is crucial for interpreting and applying GPDs.
Purpose of the Study:
- To outline a method for determining a sufficiently rich parameter space for GPDs.
- To represent experimentally observed crystal structures from the Cambridge Structural Database.
- To address the discrepancy in the number of parameters required for GPDs.
Main Methods:
- Utilized group-theoretical methods for enumerating symmetry breakings in statistical mechanical searches.
- Applied methods to a dataset of experimentally observed crystal structures from the Cambridge Structural Database.
- Determined the minimum number of parameters required to adequately represent the data.
Main Results:
- Developed a method to define the parameter space for GPDs.
- Found that 15 parameters are sufficient to represent the crystal structures of the test data.
- Contrasted this finding with literature suggesting thousands of parameters for intermolecular potentials.
Conclusions:
- The study provides a method for defining GPD parameter space, essential for their practical application.
- The finding of 15 sufficient parameters simplifies GPD construction and interpretation for molecular crystals.
- Implications for deriving GPD parameters from detailed intermolecular potentials and interpreting their meaning are discussed.
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