Accurate simulation of surfaces and interfaces of ten FCC metals and steel using Lennard\u2013Jones potentials

Krishan Kanhaiya,Wonpil Im,Hendrik Heinz,Seonghan Kim

doi:10.1038/s41524-020-00478-1

Krishan Kanhaiya, Wonpil Im + Show 2 more

Open Access

https://doi.org/10.1038/s41524-020-00478-1

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Abstract

The earlier integration of validated Lennard–Jones (LJ) potentials for 8 fcc metals into materials and biomolecular force fields has advanced multiple research fields, for example, metal–electrolyte interfaces, recognition of biomolecules, colloidal assembly of metal nanostructures, alloys, and catalysis. Here we introduce 12-6 and 9-6 LJ parameters for classical all-atom simulations of 10 further fcc metals (Ac, Ca (α), Ce (γ), Es (β), Fe (γ), Ir, Rh, Sr (α), Th (α), Yb (β)) and stainless steel. The parameters reproduce lattice constants, surface energies, water interfacial energies, and interactions with (bio)organic molecules in 0.1 to 5% agreement with experiment, as well as qualitative mechanical properties under standard conditions. Deviations are reduced up to a factor of one hundred in comparison to earlier Lennard–Jones parameters, embedded atom models, and density functional theory. We also explain a quantitative correlation between atomization energies from experiments and surface energies that supports parameter development. The models are computationally very efficient and applicable to an exponential space of alloys. Compatibility with a wide range of force fields such as the Interface force field (IFF), AMBER, CHARMM, COMPASS, CVFF, DREIDING, OPLS-AA, and PCFF enables reliable simulations of nanostructures up to millions of atoms and microsecond time scales. User-friendly model building and input generation are available in the CHARMM-GUI Nanomaterial Modeler. As a limitation, deviations in mechanical properties vary and are comparable to DFT methods. We discuss the incorporation of reactivity and features of the electronic structure to expand the range of applications and further increase the accuracy.

Highlights

Metals and alloys have been historically used in jewelry, accessories, load-bearing structures, and electrical circuitry.Advances in synthesis, characterization, and modeling in recent decades have enabled the exploration of metal nanostructures in catalysts, electrode materials, sensors, therapeutics, and electric circuits[1,2,3,4]
The deviations under 0.05% are a factor 10 smaller compared to density functional calculations (DFT) calculations and comparable to Embedded atom models (EAM)
We introduced 12-6 and 9-6 Lennard–Jones parameters for the simulation of 10 fcc metals including iron and the interfaces with electrolytes, organic, and inorganic compounds

Summary

INTRODUCTION

Metals and alloys have been historically used in jewelry, accessories, load-bearing structures, and electrical circuitry. The models accurately predict interactions of metal surfaces with solvents[16], electrolytes, and recognition mechanisms of organic molecules (Supplementary Fig. 1a)[17,18,19,20]. The positions, electron density maps, band structure, bulk properties, number of fit parameters tends to be high and specific interaction and chemical reactions can be studied without limitations on parameters with other species need to be derived for every metal, chemical composition. Deviations of computed lattice comparison, LJ parameters function in high accuracy using standard combination rules and need only 2 parameters per parameters, surface energies, and mechanical properties from metal including all interfaces. Metal surface forms, parameters, validation, and example applications to energies often deviate by 50% from experimental data using aqueous interfaces, iron alloys, and surface reactions.

DISCUSSION

METHODS

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