Predictive Power of Embedded-Atom Method (EAM) Force Fields for Lithium

Predictive Power of Embedded-Atom Method (EAM) Force Fields for Lithium

 

Joseph R. Vella¹, Mohan Chen², Emily A. Carter^2,3, Frank H. Stillinger⁴, Athanassios Z. Panagiotopoulos¹, and Pablo G. Debenedetti¹

¹Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA

 

²Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ, 08544, USA

 

³Andlinger Center for Energy and the Environment and Program in Applied and Computational Mathematics, Princeton University, Princeton, NJ, 08544, USA

 

⁴Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA

 

ABSTRACT

Six classical lithium potentials are evaluated by testing their ability to predict coexistence properties and liquid-phase radial distribution functions. All potentials are of the embedded-atom method (EAM) type.  Experimental data are used to assess the predictive ability of each potential.  It is concluded that the force field developed by Cui et al.¹ is the most reliable and robust force field, because it yields reasonable agreement for most of the properties examined.  For example, the zero-pressure melting point of this force field is shown to be approximately 443 K, while it is experimentally known to be 454 K.  This force field also gives good agreement with saturated liquid densities and liquid-phase radial distribution functions, despite the fact that no liquid-phase data were used during the fitting procedure.  Next, we used this potential to calculate the viscosity, self-diffusion coefficient, and structural properties of liquid lithium.  Our results are compared to experimental data and first-principles simulations (which utilize orbital-free density functional theory).  Both classical and first-principles simulations have their respective strengths and weaknesses.  With respect to transport properties, both simulation methods agree well with each other and yield good agreement with experimental results.  This study demonstrates the importance of force field validation as well as the benefits of using both first-principles and classical simulation methods to study a variety of materials.  The cooperation of classical and first-principles techniques can be used to study systems with limited experimental data.

 

References

 

[1] Z. Cui, F. Gao, Z. Cui and J. Qu, “Developing a Second Nearest-Neighbor Modified Embedded Atom Method Interatomic Potential for Lithium”, Modelling and Simulation in Materials Science and Engineering, 2012, 20, 015014.

[2] J. R. Vella, F. H. Stillinger, A. Z. Panagiotopoulos and P. G. Debenedetti, “A Comparison of the Predictive Capabilities of the Embedded-Atom Method and Modified Embedded-Atom Method Potentials for Lithium”, The Journal of Physical Chemistry B, 2014, DOI: 10.1021/jp5077752.

[3] M. Chen, J. R. Vella, F. H. Stillinger, E. A. Carter, A. Z. Panagiotopoulos and P. G. Debenedetti, “Liquid Li Structure and Dynamics: A Comparison Between OFDFT and Second Nearest-Neighbor Embedded-Atom Method”, AIChE Journal, 2015, DOI: 10.1002/aic.14795