Dresden 2017 – wissenschaftliches Programm
MM 55.2: Vortrag
Donnerstag, 23. März 2017, 10:30–10:45, BAR 205
Quantification of different atomic environments by a 2d structure map — •Jan Jenke1, Aparna Puchakayala Appaiah Subramanyam1, Thomas Hammerschmidt1, David G. Pettifor2, and Ralf Drautz1 — 1ICAMS Ruhr-Universität Bochum, Bochum, Germany — 2University of Oxford, Oxford, United Kingdom
The assessment of the geometric (dis)similarity of crystal structures is a central requirement to facilitate information on structural stability with applications ranging from machine-learning of DFT data to the development of effective interaction models. The moments theorem relates the moments of the local electronic density of states to the local geometric environment of an atom. The moments of the electronic density of states therefore may be viewed as descriptors from which the local atomic surrounding of an atom may be reconstructed. By restricting our analysis to the two most important moments we map the phase space of possible atomic surroundings onto a two-dimensional space. Each local atomic environment corresponds to a point on the map and the entirety of all atomic environments forms a two-dimensional structure map. We apply the structure map to determine differences in the local atomic surrounding of known crystal structures, random structures, transformation paths and molecular dynamics trajectories. We show that our two-dimensional structure map leads to a natural separation of crystal structures that one would argue are very different while crystal structures that are similar are grouped close together. We suggest that our structure map is able to sample the space of atomic surroundings in a formal locally but at the same time intuitive way.