ICAMS / Interdisciplinary Centre for Advanced Materials Simulation

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Solid‐liquid interface free energies extracted from the reweighted path ensemble

Date: 08.08.2012
Place: ICERM ‘Bridging Scales in Computational Polymer Chemistry, Providence, USA

Jutta Rogal

The solid‐liquid interface free energy is one of the important interfacial properties that govern nucleation and growth during solidification processes. It is extremely difficult to measure experimentally and various theoretical approaches have been developed to extract solid‐liquid interface energies from atomistic simulations.

If the free energy surface (FES) that maps out the transition from a single phase into the coexistence region of the two phases is known, the interface energy can be extracted from the excess energy. [1]

Here, we use the reweighted path ensemble (RPE)[2] to obtain the FES for a solid‐liquid phase transformation in a Lennard‐Jones model system. One of the key advantages of the RPE is that an a priori definition of collective variables is not required. Once the sampling has been performed the RPE allows for a projection of the FES into any arbitrary collective variable space. Furthermore, the RPE can be used to analyse committor projections, identify transition state regions, and optimise non‐linear reaction coordinates to determine important parameters governing the transformation mechanism.

[1] S. Angioletti‐Uberti et al., Phys. Rev. B 81, 125416 (2010)
[2] J. Rogal et al., J. Chem. Phys. 133, 174109 (2010)

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