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arXiv · 1811.09707

Relaxation Augmented Free Energy Perturbation

Ying-Chih Chiang·Livia B. Pártay·Guanglian Li·Christopher Cave-Ayland·Marley L. Samways·Frank Otto·Jonathan W. Essex
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Abstract

Inspired by the recent development on calculating the free energy change via a relaxation process [Nat. Phys. 14, 842 (2018)], we investigate the role of heat released in an irreversible relaxation following a large perturbation. Utilizing a derivation without microscopic reversibility, we arrive at a new free energy estimator that employs a volume term to account for missing important rare events. Applications to harmonic oscillators and particle insertion in Lennard-Jones fluid agree well with the (numerical) exact solutions. Our study hence suggests an alternative interpretation to the insufficient sampling problem in free energy calculations.

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Ying-Chih Chiang, Livia B. Pártay, Guanglian Li, Christopher Cave-Ayland, Marley L. Samways, Frank Otto, Jonathan W. Essex. 2018-11-03. Relaxation Augmented Free Energy Perturbation. https://arxiv.org/abs/1811.09707

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