Computational Techniques for Predicting Mechanical Properties of Organic Crystals: A Systematic Evaluation
- 5 March 2019
- journal article
- research article
- Published by American Chemical Society (ACS) in Molecular Pharmaceutics
- Vol. 16 (4), 1732-1741
- https://doi.org/10.1021/acs.molpharmaceut.9b00082
Abstract
Understanding of the structure – mechanical properties relationship in organic crystals can potentially facilitate the design of crystals with desired mechanical properties through crystal engineering. To understand and predict crystal mechanical properties, including tableting behavior, a number of computational methods have been developed to analyze crystal structure. These include visualization, attachment energy calculations, topological analysis, energy framework, and elasticity tensor calculation. However, different methods often lead to conflicting predictions. There is a need for a computational tool kit for predicting crystal mechanical properties from crystal structures. Using α-oxalic acid anhydrous (OAA) and dihydrate (OAD) as a model system, we have systematically compared the predictive accuracy of the experimentally determined mechanical properties using powder compaction and nanoindentation of several methods. We have found that crystal plasticity can be accurately predicted based on energy framework combined with topological analysis and DFT calculated elasticity tensor. Although very useful in characterizing crystal packing features, structure visualization, topology analysis, and attachment energy calculations alone are insufficient for accurately identifying the slip planes and predicting mechanical properties and tableting behavior of organic crystals.Keywords
This publication has 53 references indexed in Scilit:
- On the Links Between Elastic Constants and Effective Elastic Behavior of Pharmaceutical Compacts: Importance of Poisson’s Ratio and Use of Bulk ModulusJournal of Pharmaceutical Sciences, 2013
- Effect of dehydration on the mechanical properties of sodium saccharin dihydrate probed with nanoindentationCrystEngComm, 2011
- Nanoindentation Method To Study Slip Planes in Molecular Crystals in a Systematic MannerCrystal Growth & Design, 2011
- Mechanical Anisotropy in Crystalline Saccharin: Nanoindentation StudiesCrystal Growth & Design, 2010
- Azobenzene at coinage metal surfaces: Role of dispersive van der Waals interactionsPhysical Review B, 2009
- Hydrogen migration in oxalic acid di-hydrate at high pressure?Chemical Communications, 2009
- Measurement of hardness and elastic modulus by instrumented indentation: Advances in understanding and refinements to methodologyJournal of Materials Research, 2004
- From molecules to solids with the DMol3 approachThe Journal of Chemical Physics, 2000
- Evaluating the hardness, Young's modulus and fracture toughness of some pharmaceutical crystals using microindentation techniquesJournal of Materials Science Letters, 1989
- Temperature-dependence studies of α-oxalic acid dihydrateActa crystallographica Section B, Structural science, crystal engineering and materials, 1985