Mohamed Sayed Abdel Kader

An approximate empirical isotropic interatomic potential for xenon interaction is developed by simultaneously fitting the Morse-Morse-Morse Spline van der Waals potential form to interaction second pressure virial coefficient, viscosity, thermal conductivity and depolarized interaction-induced light scattering data. Absolute zeroth and second moments of the two-body depolarized spectrum have been measured and compared with theoretical calculations using various models for the interatomic potential. In additions, vibrational energy levels, third pressure virial coefficient and self-diffusion calculated for the new potential are compared with experimental ones. The results show that it is the most accurate potentials yet reported for this system. The use of the new potential in lattice sum calculations yields good results for several properties of solid xenon.

Isotropic and anisotropic collision-induced light scattering spectra of helium gas at room temperature 294.5 K and at 99.6 K with the second pressure virial coefficients, second acoustic virial coefficients, viscosity and thermal conductivity have been used for deriving the empirical models of the pair-polarizability trace and anisotropy and the interaction potential. Theoretical zeroth and second moments of the binary spectra using various models for the pair-polarizabilities and interatomic potential are compared with the experimental values performed by Le Duff's group. In addition, third pressure virial coefficients, isotopic thermal factors, self diffusion coefficients, second virial dielectric constants and second Kerr coefficients calculated for these models are compared with experimental ones. The results show that these models are the most accurate models reported to date for this system.