Conference abstracts

Session A7 - Stochastic Computation

July 11, 17:00 ~ 17:25 - Room B2

Modeling aggregation processes of Lennard-Jones particles via stochastic networks

Maria Cameron

University of Maryland, USA   -   cameron@math.umd.edu

An isothermal aggregation process of particles/atoms interacting according to the Lennard-Jones pair potential is modeled by mapping the energy landscapes of each cluster size N onto stochastic networks, computing transition probabilities for the network for an N-particle cluster to the one for N + 1, and connecting these networks into a single joint network. The attachment rate is a control parameter. The resulting network representing the aggregation and dynamics of up to 14 Lennard-Jones particles contains 6417 vertices. It is not only time-irreversible but also reducible. To analyze its transient dynamics, we introduce the sequence of the expected initial and pre- attachment distributions and compute them for a wide range of attachment rates and three values of temperature. As a result, we find the most likely to observe configurations in the process of aggregation for each cluster size. We examine the attachment process and conduct a structural analysis of the sets of local energy minima for every cluster size. We show that both processes taking place in the network, attachment and relaxation, lead to the dominance of icosahedral packing in small (up to 14 atom) clusters.

Joint work with Yakir Forman (Yeshiva University, USA).

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