Anharmonic contribution to the Gr neisen parameters of solid argon, krypton and xenon

Recent calculations of the anharmonic contribution to the Helmholtz energy of a face-centred cubic lattice with arbitrary nearest-neighbour central forces are used to estimate possible anharmonic contributions to the thermodynamic Grüneisen parameters of solid argon, krypton and xenon. For a Lennard-Jones 12-6 potential the anharmonic contribution to the Grüneisen parameter γ is found to be large and such that γ(Xe) > γ(Kr) > γ(Ar). The calculations also suggest that for these solids γ( T ) should be quite rapidly decreasing well before the melting point.