Regensburg 2019 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MM: Fachverband Metall- und Materialphysik
MM 34: Methods in Computational Materials Modelling (methodological aspects, numerics)
MM 34.10: Vortrag
Donnerstag, 4. April 2019, 12:45–13:00, H44
Characterization of local structure using a mixed radial, orientational three-body correlation function — •Martin H. Mueser and Sergey V. Sukhomlinov — Universität des Saarlandes, 66123 Saarbrücken, Germany
Computer simulations of condensed matter systems are often run with the goal to ascertain the degree to which the local structure of a system lacking long-range order resembles that of crystalline reference phases. As a tool for such analysis we propose a mixed radial, orientational three-body correlation function, i.e., gABC(rBC, ϑABC). This function is defined to be proportional to the probability of finding an atom of type C at a distance rBC under an angle of ϑABC given that rAB is within 10% of a typical AB bond length or AB nearest-neighbor distance. This correlation function allows the local order in disordered systems to be more easily related to that of reference crystals than with other methods that have so far been conventionally used. This method could also be used to detect and quantify local symmetries.
In order to demonstrate the use of the analysis and its usefulness, a visual library of mono- and two-component crystals is produced and compiled, and then applied to a diverse body of selected liquids and disordered solids. These include the analysis of the extent with which liquid Lennard-Jonesium and liquid copper resemble face-center-cubic or hexagonal close packing, the relative amount of cristobalite in a simple model of liquid silica, the extend of the Peierls deformation in liquid antimony and the identification of the seesaw molecular geometry occurring in zinc-phosphates under pressure.