  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.
