On fitting a gold embedded atom method potential using the force matching method.

Area of Science:

• Materials Science
• Computational Materials Science
• Condensed Matter Physics

Background:

• The Embedded Atom Method (EAM) is a widely used atomistic simulation technique.
• Accurate interatomic potentials are crucial for reliable materials simulations.
• Previous EAM potentials for gold have limitations in accurately describing various material properties.

Purpose of the Study:

• To develop an improved EAM potential for gold using an enhanced fitting methodology.
• To assess the performance of the new potential against experimental data and previous models.
• To investigate the fundamental limitations of the EAM framework.

Main Methods:

• Developed a new gold EAM potential utilizing an improved force matching methodology.
• Fitted the potential to high-temperature solid lattice constants and liquid densities.
• Compared the new potential's predictions with experimental data and established potentials (FBD, Johnson, glue model).

Main Results:

• The new EAM potential shows significant improvements in agreement with experimental lattice constants, elastic constants, stacking fault energy, and radial distribution functions.
• Surface energy was slightly improved, but vacancy formation energy was slightly inferior compared to some previous potentials.
• A brute force fitting approach to all properties simultaneously was unsuccessful, indicating inherent limitations within the EAM framework.

Conclusions:

• The improved fitting methodology offers a path towards more accurate EAM potentials for gold and potentially other metals.
• Fundamental limitations exist within the EAM framework, particularly in simultaneously fitting disparate properties like surface energy and liquid lattice constants.
• Further advancements may require modifications beyond the standard EAM structure to overcome these inherent constraints.