New anisotropic potential energy surfaces for N₂-Ne and N₂-Ar

Abstract

New anisotropic potential energy surfaces of the Hartree-Fock plus damped dispersion (HFD) type have been obtained for the N2-Ne and N2-Ar interactions. The SCF energies utilized in constructing the short-range part of the interactions were computed at 20 points on each surface by using basis sets of double zeta plus polarization quality. Anisotropic C 6 and Cs dispersion coefficients, utilized in constructing the long-range part of the interaction, have been calculated with a recently obtained combining rule. Several procedures are introduced for estimating the anisotropic damping factors used in the description of the correlation energy contributions in the HFD model. The essential differences amongst the surfaces reported here arise from these estimates. Comparisons are made with other available anisotropic N2-Ne and N2-Ar surfaces. The predictive ability of all surfaces with respect to the temperature dependence of the interaction second virial coefficient, BI2(T ), has also been tested. For the N2-Ne system only the present HFD3 surface gives good agreement with the experimental interaction second virial coefficients over a wide temperature range. Similarly, for the Nz-Ar system the surface of Candori et al. [1983, Chem. Phys. Lett., 102, 412], which was partially determined using the second virial coefficient data, and the present HFD1 surface give good agreement with experimental virial data.

Microwave spectra of the Ne–N2 Van der Waals complex: Experiment and theory

“…[6][7][8][9] The single minimum occurring for the T-shaped configuration for each of these potential surfaces has been confirmed by the ab initio results. A secondary minimum for the linear configuration is removed by the basis set superposition error correction.…”

“…Four previous potential surfaces [6][7][8][9] for the Ne-N 2 interaction, two of them fully empirical, 6,9 the other two semiempirical, 7,8 are available for use in theoreti-a͒ Present address: School of Chemistry, University of Melbourne, Parkville, Victoria 3052, Australia. cal simulations of the MW spectrum.…”

Low-Temperature Rotational Relaxation of N2 in Collisions with Ne

“…The most thorough multiproperty check of an intermolecular potential energy surface for the N 2 /Ne interaction was performed by Wong et al 21 on the HFD3 PES. 25 These authors performed classical trajectory (CT) and infinite order sudden (IOS) calculations of an extensive set of effective cross sections governing a wide variety of transport and relaxation phenomena for Ne/N 2 mixtures. As far as we know, the only theoretical σ r,N2-Ne (T t ) data available are the CT values reported in this work, corresponding to the 77-673 K temperature interval; over this range, the CT cross sections grow also with decreasing T t .…”

Theoretical studies of van der Waals molecules and intermolecular forces

“…Mettes et al212 measured the Zeeman spectrum of Ar-02 and found that it was in somewhat better agreement with the modified potential of ref 211 than with the original one. McCourt et al 213 have extended the semiempirical models71 for He-N2 to obtain potentials for Ne-N2 and Ar-N2 and have tested the resulting potentials against experimental second virial coefficients; all their potentials have substantially more anisotropy in the position of the repulsive wall than the empirical potentials. Ling et al 214 have also developed semiempirical potentials for Ne-N2 and have compared calculated second virial coefficients, viscosities, and diffusion coefficients with experimental values.…”