Multipole moments, polarizabilities and anisotropic long range interaction coefficients for N₂

Abstract

This paper contains results for the permanent multipoles, the multipole polarizabilities and the related anisotropic long range interaction coefficients C5 to C10 (complete) for the nitrogen molecule. The electrostatic, induction and dispersion interaction coefficients have been calculated using ab initio SCF wavefunctions ; better estimates for the dispersion terms have been obtained by an approximate procedure, which uses the accurate (semi-) empirical data available for Co and the dipole polarizability, in combination with the ab initio results. The pure quadrupole-quadrupole anisotropy appears to be substantially modified by the dispersion anisotropy and, to a smaller extent, by the higher multipole electrostatic interactions ; the induction energy can be neglected. The dispersion anisotropy factors ys and )'10, are much larger than Y6, due to the occurrence of the (completely anisotropic) mixed-pole terms. The recently proposed non-empirical Uns61d method yields results which support applications to larger molecules.

Quantum chemical and statistical thermodynamic investigations of anesthetic activity. 3. The interaction between CH4, CH3Cl, CH2Cl2, CHCl3, CCl4, and an O—H … O hydrogen bond

“…cules. The coefficients C,, for H, C, 0 , and C1 were determined and from C6 terms of the (H20), and CC1,H.. .OH, complexes which, in turn were evaluated by using the non-empirical Un-[2] AGTO = -RT In KT sold approximation (12)(13)(14). It is clear from the definition of Conditions favoring the right hand side in [l] were found to be: (a) favorable changes in polar interactions in the Hartree-Fock energy, (b) dispersion interactions, and (c) favorable (i.e.…”

Hindered internal rotations in Van der Waals molecules and molecular crystals

“…An important part of this work is concerned with extracting empirical N 2 -N 2 interaction potentials [3] from the experimental data. Recently, a detailed N 2 -N 2 potential has been obtained from ab initio calculations [8,9]. This potential has been successfully used in lattice dynamics studies [10] on a and 7 N 2 and, at the same time, in accurate dynamical calculations [11] on the Van der Waals molecule (N 2 )2-In the present paper, we discuss some new results and ways to extract further useful information.…”

“…The expression in brackets is a 3-j symbol [18]. The ab initio calculations [8,9] have demonstrated that anisotropic terms in potential (1) up to LA = Lb = 4 inclusive are important; actually some higher terms were included as well [9]. Summing this potential over six shells (86 neighbouring molecules), just as Dunmore [16], but making no further approximations, mean-field calculations have been carried out [19] for o:-N2 in the cubic Pa3 structure [4].…”

Molecular alignment in a shock wave

“…8,9 The parameters for all models are chosen such as to best reproduce experimental data or come from ab initio calculations. [10][11][12] Large-scale Molecular Dynamics simulations of a shock wave in nitrogen have been performed. A simple a two-center Lennard-Jones potential, i.e., not accounting for Coulombic interactions, was employed.…”