Evaluation and optimisation of interface force fields for water on gold surfaces

Berg, Andrej and Peter, Christine and Johnston, Karen (2017) Evaluation and optimisation of interface force fields for water on gold surfaces. Journal of Chemical Theory and Computation. ISSN 1549-9618 (https://doi.org/10.1021/acs.jctc.7b00612)

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Abstract

The structure and dynamics of water at gold surfaces is important for a variety of applications, including lab on a chip and electrowetting. Classical molecular dynamics (MD) simulations are frequently used to investigate systems with water-gold interfaces, such as biomacromolecules in gold nanoparticle dispersions, but the accuracy of the simulations depends on the suitability of the force field. Density functional theory (DFT) calculations of a water molecule on gold were used as a benchmark to assess force field accuracy. It was found that Lennard-Jones potentials did not reproduce the DFT water-gold configurational energy landscape whereas the softer Morse and Buckingham potentials allowed for a more accurate representation. MD simulations with different force fields exhibited rather different structural and dynamic properties of water on a gold surface. This emphasises the need for experimental data and further effort on the validation of a realistic force field for water-gold interactions.