Molecular dynamics study of solid argon with N2, O2, and CO impurities

Molecular dynamics calculations employing atom–atom (exp-6) potentials are reported for solid argon in which 5% of the lattice sites are occupied by diatomic molecules. At temperatures close to the melting point (T ~ 80 K) the molecules are reorienting rapidly with no preferred orientation. Upon cooling, however, a distinct preference is observed for the crystallographic [Formula: see text] direction. Power spectra that characterize the translational and reorientational motions in the system have been evaluated. The results are discussed in light of available experimental data.