Dresden 2014 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 9: Crystallization, Nucleation and Self Assembly II
CPP 9.2: Vortrag
Montag, 31. März 2014, 15:30–15:45, ZEU 260
The Flexible Rare Event Sampling Harness System (FRESHS) — Kai Kratzer1, Joshua Berryman2, Aaron Taudt1, Johannes Zeman1, and •Axel Arnold1 — 1Institut für Computerphysik, Universität Stuttgart, Germany — 2Theory of Soft Condensed Matter, University of Luxembourg, Luxembourg
Nucleation is a rare event that is computationally expensive to study in brute force computer simulations. Special sampling techniques can reduce this effort. We present the Flexible Rare Event Sampling Harness System (FRESHS), an open source software framework (http://www.freshs.org) that provides Forward Flux Sampling (FFS) and Stochastic Process Rare Event Sampling (S-PRES), which are two such methods well suited to study nucleation events.
Several features of FRESHS make its application particularly easy. FFS or S-PRES only require an order parameter that describes the progress of the rare event and allows to split the transition into milestones or interfaces. Our FFS implementation features automatic interface placement, which ensures optimal flux through all interfaces without the need of expert knowledge. `Ghost' runs overcome the computational bottleneck of waiting for the last trial simulation when advancing to the next interface. FRESHS can steer popular Molecular Dynamics codes such as GROMACS, LAMMPS or ESPResSo, and other software can be attached through a simple plugin system. Our framework allows for checkpointing and flexible analysis already during runtime, and is suitable for single workstations up to large compute clusters.