(731c) 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