Solid-liquid coexistence of the noble elements. I. Theory illustrated by the case of argon

Abstract

The noble elements constitute the simplest group of atoms. At low temperatures or high pressures they freeze into the face-centered cubic (fcc) crystal structure (except helium). We perform molecular dynamics using the recently proposed simplified ab initio atomic (SAAP) potential [Deiters and Sadus, J. Chem. Phys. 150, 134504 (2019)] . This potential is parameterized using data from accurate ab initio quantum mechanical calculations by the coupled-cluster approach on the CCSD(T) level. We compute the fcc freezing lines for Argon and find a great agreement with the experimental values. At low pressures, this agreement is further enhanced by using many-body corrections. Hidden scale invariance of the potential energy function is validated by computing lines of constant excess entropy (configurational adiabats) and shows that mean square displacement and the static structure factor are invariant. These lines (isomorphs) can be generated from simulations at a single state-point by having knowledge of the pair potential. The isomorph theory for the solid-liquid transition is used to accurately predict the shape of the freezing line in the pressure-temperature plane, the shape in the density-temperature plane, the entropy of melting and the Lindemann parameters along the melting line. We finally predict that the body-centered cubic (bcc) crystal is stable at high pressures.

References in corpus (5)

• Thermodynamic interpretation of the scaling of the dynamics of supercooled liquids
• Strong pressure-energy correlations in van der Waals liquids
• How short-range attractions impact the structural order, self-diffusivity, and viscosity of a fluid
• Intermolecular distance and density scaling of dynamics in molecular liquids
• The FCC-BCC-Fluid triple point for model pair interactions with variable softness

Cited by in corpus (5)

• Freezing density scaling of fluid transport properties: Application to liquefied noble gases
• Theory of melting lines
• Optical and spin-coherence properties of rubidium atoms trapped in solid neon
• Estimating melting curves for Cu and Al from simulations at a single state point
• Isomorphs in sheared binary Lennard-Jones glass: Transient response