The anisotropic potentials of He–N2, Ne–N2, and Ar–N2

Abstract

The anisotropic potentials of He–N2, Ne–N2, and Ar–N2 are predicted using the Tang–Toennies potential model. This model damps the long-range ab initio dispersion terms individually using a universal damping function and adds to this a simple Born–Mayer repulsive term. The Born–Mayer parameters for the three systems were derived from SCF calculations. The dispersion coefficients were estimated from established combining rules using an effective multipole spectrum for the N2 molecule computed by Visser and Wormer from the time-dependent coupled Hartree–Fock approximation. The resulting potentials were used to predict the second interaction virial coefficients for each system, and they are found to be in excellent agreement with experiment. It is concluded that the spherical symmetric potentials are within 2%–3% of the true potentials. Some discrepancies with recent molecular beam experiments appear to be present, however, for the anisotropies especially in the case of He–N2. Finally, it is found that the law of corresponding states for anisotropic systems, which predicts that the reduced shapes of the potentials for a given geometrical configuration are identical, also holds for the highly anisotropic rare gas–N2 systems.

Monte Carlo simulation studies of diffusion coefficients and mobilities for Rb+–N2 with anisotropic model potential and comparison with experimental measurements

“…17,18 The model potential works very well especially on closed shell ion-atom systems. In the present study, the Tang-Toennies potential model 18,19 for inert gas atom-nitrogen molecule is extended to the case for the closed shell Rb ϩ -N 2 molecule system. Based on this extension, we construct an anisotropic potential for Rb ϩ -N 2 pair.…”

“…1 ␣ q is estimated from an approach recommended by Margenau and Kestner. 22 The dispersion coefficients C 6 , C 8 , C 10 for Rb ϩ -N 2 are determined by the combining rule, 18 in which the dispersion coefficients of Rb ϩ -Rb ϩ and N 2 -N 2 are used as input. Among the dispersion coefficients of ion and molecule, the C 6 and C 8 dispersion coefficients for Rb ϩ -Rb ϩ are evaluated by using the method of Koutselos and Mason.…”

Accurate intermolecular ground state potential of the Ne–N2 van der Waals complex

“…To evaluate the spectra, they use a model based on anisotropic atom-atom interactions, that employs a simple additive approximation for the Ne-N 2 IPES in terms of NeN potentials. Among the previously available potential energy surfaces those of Bowers et al 5 and Beneventi et al 6 were selected to compare with. The former gave rather irregular deviations from the experimental values for different groups of microwave lines and for the latter the deviations were quite uniform, but the Jäger et al surface clearly improved these results, given deviations that could be reduced to within 0.05% by a single-parameter scaling.…”

Investigation of the ArN+2 ion by dissociative ionization of argon/nitrogen clusters

“…The binding energy of neutral ArN 2 was calculated to be 13.9 meV. 22 The geometry of neutral ArN 2 is triangular. The structure and the energy of ArN 2 ϩ as well as ͑N 2 ͒ 2 ϩ have been investigated by means of ab initio calculations by Frecer et al 23 At the UHF/6-31G͑d͒ level of theory the most stable conformation of ArN 2 ϩ was found to be linear in that work.…”