Critical assessment of UO2 classical potentials for thermal conductivity calculations

Chernatynskiy, Aleksandr V.; Flint, Charles Louis; Sinnott, Susan B.; Phillpot, Simon R.

doi:10.1007/s10853-011-6230-0

Cited by 54 publications

(41 citation statements)

References 35 publications

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“…Other authors have experienced situations where a potential can obtain proper phonon dispersion but incorrect thermal conductivity. 39 We note that this stresses the importance of fitting to both the 2nd and higher order interatomic force constants (IFCs), since the 2nd order IFCs determine the phonon dispersion, while the higher order IFCs are also needed to determine the thermal conductivity. The validity of an approximately 10% error in force, energy and stress metric, along with <10% errors in IFCs is consistent with estimations of the thermal conductivity for c-Si using the Boltzmann transport equation within the relaxation time approximation as implemented in Alamode.…”

Section: Discussionmentioning

confidence: 95%

Empirical interatomic potentials optimized for phonon properties

et al. 2017

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Molecular dynamics simulations have been extensively used to study phonons and gain insight, but direct comparisons to experimental data are often difficult, due to a lack of accurate empirical interatomic potentials for different systems. As a result, this issue has become a major barrier to realizing the promise associated with advanced atomistic-level modeling techniques. Here, we present a general method for specifically optimizing empirical interatomic potentials from ab initio inputs for the study of phonon transport properties, thereby resulting in phonon optimized potentials. The method uses a genetic algorithm to directly fit the empirical parameters of the potential to the key properties that determine whether or not the atomic level dynamics and most notably the phonon transport are described properly.

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Section: Discussionmentioning

confidence: 95%

Empirical interatomic potentials optimized for phonon properties

et al. 2017

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“…In other simple crystalline solids, including Si, 21,22 UO 2, 23 and MgSiO 3 , 24 such classical potentials may predict thermal conductivity to be different from the experimental values by a factor of two or more; similar discrepancies are observed among different parameterizations of potentials developed for the same system. It is anticipated that this variability among the predictions of various potentials should be less of a problem for solid argon due to its completely filled electronic shell, which results in relatively simple interatomic interactions.…”

Section: Simulation Methodsmentioning

confidence: 92%

Thermal conductivity of argon at high pressure from first principles calculations

Chernatynskiy

Phillpot

2013

Journal of Applied Physics

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We present calculations of the thermal conductivity of fcc Argon at high pressures (pressure range is 10-150 GPa, temperatures range is 400-1200 K) from first principles in the framework of density functional theory and solution of the Boltzmann Transport Equation. Local density approximation (LDA) and generalized gradient approximation (GGA) produce similar thermal conductivities, with differences accounted by the known overbinding and underbinding of the LDA and GGA, correspondingly. Thermal conductivities at all considered pressures and temperatures are found to be consistent with the results of previous molecular dynamics simulations based on classical 2-body potentials. However, they are not consistent with recent experimental findings. Possible reasons for this disagreement are discussed. In addition, in light of our calculations, we critically examine analytically tractable approximations for thermal conductivity as applied to solid argon. V C 2013 AIP Publishing LLC. [http://dx.

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“…Accurately reproducing the thermophysical properties of UO 2 , such as the lattice parameter, elastic constants, thermal conductivity and specific heat over a wide range of temperatures, has often been used as a key discriminators for the suitability of different potential sets [21][22][23][24]. Similarly, Potashnikov et al [25] compared the ability of a number of interatomic potentials to predict oxygen diffusivity in UO 2 using MD.…”

Section: Introductionmentioning

confidence: 99%