Comparison of Lennard-Jones and Exponential-Six Pair Potentials for Solid Argon at Low Pressure

Hoover, William G.; Holt, Albert C.; Shortle, David; Gray, Steven G.

doi:10.1063/1.1673217

Cited by 5 publications

(2 citation statements)

References 12 publications

(9 reference statements)

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“…The former description corresponds to the existing interaction between two Ar, or between a Ar and N atom. The potential parameters (energies in Hartree, distances in Bohr radius) are ε Ar−Ar = 3.7936 * 10 −4 eH, σ Ar−Ar = 6.3302r B , [15,16] , ε Ar−N = 2.1263 * 10 −4 eH, σ Ar−N = 6.3306r B [15,17].…”

Section: Potential Description For the Discrete Atomic Modelmentioning

confidence: 99%

Inexpensive discrete atomistic model technique for studying excitations on infinite disordered media: The case of orientational glass ArN₂

González-Albuixech

Gaita‐Ariño

2015

Int. J. Numer. Meth. Engng

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Excitations of disordered systems such as glasses are of fundamental and practical interest but computationally very expensive to solve. Here we introduce a technique for modeling these excitations in an infinite disordered medium with a reasonable computational cost. The technique relies on a discrete atomic model to simulate the low-energy behavior of an atomic lattice with molecular impurities. The interaction between different atoms is approximated using a spring like interaction based on the Lennard Jones potential but can be easily adapted to other potentials. The technique allows to solve a statistically representative number of samples with a minimum of computational expense, and uses a Monte-Carlo approach to achieve a state corresponding to any given temperature. This technique has already been applied successfully to a problem with interest in condensed matter physics: the solid solution of N2 in Ar.

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Section: Potential Description For the Discrete Atomic Modelmentioning

confidence: 99%

Inexpensive discrete atomistic model technique for studying excitations on infinite disordered media: The case of orientational glass ArN₂

González-Albuixech

Gaita‐Ariño

2015

Int. J. Numer. Meth. Engng

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“…It is based on the iterative solution, using known numerical methods [27,28], of a mesh of non-linear springs with Lennard-Jones r 6 − r 12 potential [29] to describe all relevant interactions. In particular, we assumed the following Lennard-Jones parameters: Ar-Ar = 3.7936 • 10 −4 E h , σ Ar-Ar = 6.3302r B [30], [33]. Starting from a pristine Ar network imitating the crystal structure [31], we increase the concentration of N 2 step by step up to 80%, with each new impurity taking a random position and initial orientations.…”

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confidence: 99%

Inversion symmetric vs. asymmetric excitations and the low-temperature universal properties of Ar:N ₂ and Ar:N ₂ :CO glasses

Gaita‐Ariño¹,

González-Albuixech²,

Schechter³

2015

EPL

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The bias energies of various two-level systems (TLSs) and their strengths of interactions with the strain are calculated for Ar:N2 glass. Unlike the case in KBr:CN, a distinct class of TLSs having weak interaction with the strain and untypically small bias energies is not found. The addition of CO molecules introduces CO flips which form such a class of weakly interacting TLSs, albeit at much lower coupling than that at which they are typically observed in solids. We conclude that because of the absence of a distinct class of weakly interacting TLSs, Ar:N2 is a non-universal glass, the first such system in three dimensions and in ambient pressure. Our results further suggest that Ar:N2:CO may show universal properties, but at temperatures lower than ≈ 0.1 K, much smaller than the typical temperature ≈ 3 K associated with universality, because of the untypical softness of this system. Our results thus shed light on two long-standing questions regarding the low-temperature properties of glasses: the necessary and sufficient conditions for quantitative universality of phonon attenuation, and what dictates the energy scale of ≈ 3 K below which universality is typically observed.

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Radial Distribution Function for Argon: Calculations from Thermodynamic Properties and the Lennard-Jones 6:12 Potential

Davis

1971

The Journal of Chemical Physics

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The radial distribution function, g(x), of argon is calculated from thermodynamic data and the Lennard-Jones 6:12 potential. This is accomplished by introducing analytical expressions for the function Y(x) ≡ exp[φ(x) / T*]g(x) − 1 which contain a limited number of adjustable parameters. Three calculations are made. The first uses only the pressure and energy equations and reproduces g(x) accurately for x ≤ 1.5. The other two incorporate the compressibility equation and generally give accurate values of g(x) for x ≤ 2.1 and approximate values for 2.1 ≤ x ≤ 3.

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Comparison of Lennard-Jones and Exponential-Six Pair Potentials for Solid Argon at Low Pressure

Cited by 5 publications

References 12 publications

Inexpensive discrete atomistic model technique for studying excitations on infinite disordered media: The case of orientational glass ArN₂

Inexpensive discrete atomistic model technique for studying excitations on infinite disordered media: The case of orientational glass ArN₂

Inversion symmetric vs. asymmetric excitations and the low-temperature universal properties of Ar:N ₂ and Ar:N ₂ :CO glasses

Radial Distribution Function for Argon: Calculations from Thermodynamic Properties and the Lennard-Jones 6:12 Potential

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Comparison of Lennard-Jones and Exponential-Six Pair Potentials for Solid Argon at Low Pressure

Cited by 5 publications

References 12 publications

Inexpensive discrete atomistic model technique for studying excitations on infinite disordered media: The case of orientational glass ArN2

Inexpensive discrete atomistic model technique for studying excitations on infinite disordered media: The case of orientational glass ArN2

Inversion symmetric vs. asymmetric excitations and the low-temperature universal properties of Ar:N 2 and Ar:N 2 :CO glasses

Radial Distribution Function for Argon: Calculations from Thermodynamic Properties and the Lennard-Jones 6:12 Potential

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Inexpensive discrete atomistic model technique for studying excitations on infinite disordered media: The case of orientational glass ArN₂

Inexpensive discrete atomistic model technique for studying excitations on infinite disordered media: The case of orientational glass ArN₂

Inversion symmetric vs. asymmetric excitations and the low-temperature universal properties of Ar:N ₂ and Ar:N ₂ :CO glasses