Berlin 2024 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 9: Crystallization, Nucleation and Self-Assembly II

CPP 9.3: Vortrag

Montag, 18. März 2024, 15:30–15:45, H 2032

How to distinguish crystal symmetries in coarse-grained computer simulations of polymer crystallization in melts? — •Evgeniia Filimonova, Timur Shakirov, and Viktor Ivanov — Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany

We report on our recent developments in comprehensive analysis of crystalline structures arising during crystallization in polymer melts. Using flat histogram Monte Carlo simulations of a coarse-grained model, we obtain a very large number of (partially) crystalline conformations for low energies. We faced with the problem of distinguishing between different crystalline symmetries using the traditional well-known analysis based on bond order parameters, first suggested by Steinhardt and later improved by many authors, especially due to thermal noise. Additionally, some deformations of symmetries appear to be caused by inavoidable finite size effects. We have developed a new approach to calculate the bond order parameters using improved averaging of coordinates of particles, including a new method for visualization of local crystalline ordering on small scales. As a result, we were able to observe the coexistence of domains with different local crystalline symmetries, which had not previously been reported in the literature.

Keywords: Polymer crystallization; Computer simulation; Bond order parameters