ChemRxiv
These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
1/1
3 files

A New Tool for Validating Theoretically Derived Anisotropic Displacement Parameters with Experiment: Directionality of Prolate Displacement Ellipsoids

preprint
submitted on 24.05.2019, 11:23 and posted on 28.05.2019, 14:48 by Damian Mroz, Janine George, Marius Kremer, Ruimin Wang, Ullrich Englert, Richard Dronskowski
X-ray diffraction on crystalline solids provides the electron density in the unit cell, typically interpreted as atom types, fractional coordinates, and anisotropic displacement parameters (ADPs). Given the chemical composition, not only coordinates but also ADPs can be obtained from first-principles calculations. In order to validate the latter, we suggest comparing the direction of the maximum main axes for sufficiently anisotropic theoretical and experimental ellipsoids, in addition to their scalar properties. This new criterion provides additional insight: while the amplitude of motion is generally underestimated by the computationally inexpensive harmonic approximation, the relative orientation may still be in good agreement with the experimental findings. This approach can complement the already established scatter plot of main-axes components and the similarity index, and it is also chemically intuitive by giving a direct picture of the relative orientation of the ellipsoids.

History

Email Address of Submitting Author

damian.mroz@ac.rwth-aachen.de

Institution

RWTH Aachen University

Country

Germany

ORCID For Submitting Author

0000-0001-7818-5349

Declaration of Conflict of Interest

There is no conflict of interest

Exports