Atom dipole interaction model

Applequist J, Carl JR, Fung K-K (1972) Atom dipole interaction model for molecular polarizability. Application to polyatomic molecules and determination of atom polarizabilities. J Am Chem Soc... 

POL and POLl have the same three-site tetrahedral, SPC-like geometry with a charge on each site. The charge magnitude is adjusted to reproduce properties of the liquid, and the resulting dipole, 2.024 D, is much closer to the value in gas phase than for effective non-polarizable models. Polarizability, described by atomic polarizabilities obtained from the atom-dipole interaction model of Applequist et al [172] is however underestimated. POLl modifies the... 

J. Applequist. An atom-dipole interaction model for molecular optical properties. Accounts Chem. Res., 70 79-85 (1977). 

M. Neumann. Collision induced light scattering by globular molecules Applequist s atom dipole interaction model and its implementation in computer simulation. Molec. Phys., 53 187-202 (1984). 

P. L. Prasad and L. A. Nafie. The atom dipole interaction model of Raman optical activity Reformulation and comparison to the general two-group model. J. Chem. Phys., 70 5582-5588 (1979). 

P. L. Prasad and D. F. Burrow. Raman optical activity, computation of circular intensity differentials by the atom-dipole interaction model. J. Am. Chem. Soc., 707 800-805 (197y). 

J. Applequist, J. R. Carl, and K.-K. Fung, /. Am. Chem. Soc., 94, 2952 (1972). An Atom-Dipole Interaction Model for Molecular Polarizability. Application to Polyatomic Molecules and Determination of Atom Polarizabilities. 

J. Applequist, Acc. Chem. Res., 10, 79 (1977). An Atom-Dipole Interaction Model for Molecular Optical Properties. 

The atom dipole interaction model is an alternative expression of the additive approximation for vibrational intensities. It is based on the assumption that the molecular polarizability is a sum of polarizabilities of the constituent atoms. The interactions between atoms in the molecule are realized by the electromagnetic fields of induced atomic dipoles. 

Dipole Interaction Model for Molecular Polarizability. Application to Polyatomic Molecules and Determination of Atom Polarizabilities. 

In the Raman case, three distinct general computational thedries have been proposed the bond polarizability theory, the atom dipole interaction theory and localized molecular orbital theories. In the first and third of these the normal modes of vibration, and hence the vibrational quantum states, must embrace a chiral nuclear framework. They are therefore analogous to the inherently chiral chromo-phore model of electronic optical activity in which the electronic states are delo-... 

The simple dipole interaction model for polarizability has been extended later by many researchers [39-41] to form the basis of the so-called discrete dipole approximation (DDA) for calculating the optical properties of metal nanoclusters. To introduce simplification, in DDA, the nanocluster is divided into small cells (which may contain multiple number of atoms) and the response of each cell to the external field as well as the internal field of the induced dipoles at all the cells is evaluated to obtain the polarizability and optical absorption of metal nanoclusters. 

A charge-dipole interaction model has also been used [27] recently for the calculation of the freqnency-dependent polarizability of silver clnslers. Time variations of the atomic charges are shown to be related to the cnrrents that flow through... 

While nonbonded atom pairs will typically not come within 1A of each other, it is possible for covalently bound pairs, either directly bounds, as in 1-2 pairs, or at the vertices of an angle, as in 1-3 pairs. Accordingly it may be considered desirable to omit the 1-2 and 1-3 dipole-dipole interactions as is commonly performed on additive force fields for the Coulombic and van der Waals terms. However, it has been shown that inclusion of the 1-2 and 1-3 dipole-dipole interactions is required to achieve anistropic molecular polarizabilites when using isotropic atomic polariz-abilites [50], For example, in a Drude model of benzene in which isotropic polarization was included on the carbons only inclusion of the 1-2 and 1-3 dipole-dipole interactions along with the appropriate damping of those interactions allowed for reproduction of the anisotropic molecular polarizability of the molecule [64], Thus, it may be considered desirable to include these short range interactions in a polarizable force field. 

An important addition to the model was the inclusion of virtual particles representative of lone pairs on hydrogen bond acceptors [60], Their inclusion was motivated by the inability of the atom-based electrostatic model to treat interactions with water as a function of orientation. By distributing the atomic charges on to lone pairs it was possible to reproduce QM interaction energies as a function of orientation. The addition of lone pairs may be considered analogous to the use of atomic dipoles on such atoms. In the model, the polarizability is still maintained on the parent atom. In addition, anisotropic atomic polarizability, as described in Eq. (9-28), is included on hydrogen bond acceptors [65], Its inclusion allows for reproduction of QM polarization response as a function of orientation around S, O and N atoms and it facilitates reproduction of QM interaction energies with ions as a function of orientation. 

---