van der Waals induced dipoles

Abstract

Effects of van der Waals interactions on molecular dipole moments: The role of fieldinduced fluctuation correlations J. Chem. Phys. 83, 5198 (1985); 10.1063/1.449732Remarks on the magnitude of van der Waals induced dipole moments in physisorption Expressions are derived for calculating the induced dipole moment of an arbitrary molecule A interacting with an arbitrary system B through first-and second-order Coulomb interaction. The theory is formulated in terms of linear and quadratic charge-density susceptibilities and takes account of charge penetration but not exchange between the systems. The theory is specialized to the interaction of two nonoverlapping molecules and to a molecule interacting with a nonferroelectric solid, metallic, or crystalline. In the case of two interacting molecules, the induced moment is developed in inverse powers of R, the distance between the centers of the molecules, up to and including R -7; the coefficients of the series are given in terms ofthe total charges, permanent moments, polarizabilities, and hyperpolarizabilities. In the case of the solid, the results are given in terms of the molecule-solid distance Zo, the dielectric function of the solid, and the permanent moments, polarizabilities, and hyperpolarizabilities of the molecule. The expressions for the dispersion and induction dipoles derived here in terms of the charge-density (hyper) susceptibilities are the most general to date in that ionic contributions are included, and the expansion in terms of the (hyper)polarizabilities is the most explicit for nonoverlapping systems. Our results are compared with the work in the literature.

Theoretical investigation of the ethylene dimer: Interaction energy and dipole moment

“…In the framework of the long-range approximation, the induction dipole moment l a,ind and the dispersion dipole moment l a,disp through the order of R À7 are written as [61] l a;ind ¼ 1 3 …”

Forces on nuclei in interacting molecules: New analytical results obtained with nonlocal polarizability densities

“…(27). The lowest-order force on the entire A molecule varies as R -4, however, due to the sum rule in Eq.…”

“…If the charge, dipole, and quadrupole of molecule A are split into their electronic vs nuclear contributions, zeA, f-leA, and eeA vs znA, f-l nA , and e nA , then the first-order induction force on molecule A can be recast as From our analysis in Eqs. (27), (28), and (34)-(44), we conclude: each of the terms in Eq. (45) that contains the nuclear charge, dipole, or quadrupole moment on A originates in the direct interactions of the nuclear charge on A with the unperturbed charge distribution of B; each of the terms that contains the permanent electronic charge, dipole, or quadrupole moment on A originates in the attraction of the nuclei on A to the electrons on A, perturbed to first order by the interaction with B.…”

“…(27) To find the long-range limit, it is convenient first to expand r' about the origin RB in molecule B. This yields…”

Effect of van der Waals interaction on Raman transitions. I

“…(1) ordinary charge density susceptibilities have been previously defined [12]. The definitions of the transition charge-density susceptibilities will be given below after specialization to nonoverlapping molecules.…”