Thole’s model

P.Th. van Duijnen and M. Swart, Molecular and atomic polarizabilities Thole s model revisited, J. Phys. Chem. A, 102 (1998) 2399-2407. 

Thole s polarizability parameters were selected to optimize the molecular polarizabilities for a set of 16 molecules. The method was later expanded to fit 52 molecules [146], It must be emphasized that this electric-field damping method is totally independent of the polarization scheme used. For the Drude and fluctuating charge methods only /i(r) is required, whereas for methods based on induced dipoles both /i(r) and /2(r) are necessary. In the context of the induced dipole model other models were proposed since the formula of Thole does not provide enough attenuation. For example, in Ref. [152] the field is evaluated using... 

Fanourgakis, G. S., 8c Xantheas, S. S. (2008). Development of transferable interaction potentials for water. V. Extension of the flexible, polarizable. Thole-type model potential (TTM3-F, v. 3.0) to describe the vibrational spectra of water c ns-ters nd iquid wa,teT. Journal of Chemical Physics, 128, 074506. 

Burnham C J, Li J C, Xantheas S S and Leslie M 1999 The parametrization of a Thole-type all-atom polarizable water model from first prinoiples and its applioation to the study of water olusters (n = 2-21) and the phonon speotrum of ioe Ih J. Chem. Phys. 110 4566-81... 

An additional extension of the Drude model includes terms to improve the treatment of the orientation of molecular polarizabilities. Traditionally, in non-polarizable models electrostatic interactions, as well as LJ terms, between atoms bonded to each other or separated by two covalent bonds, 1,2 and 1,3 pairs, respectively, are ignored. Similarly, in the Drude model the interactions between core charges as well as those between the Drude oscillators and core charges are excluded for 1-2 and 1-3 pairs. However, the ability to preserve Coulomb interactions between Drude oscillators (i.e., dipole-dipole interactions) for the 1,2 and 1,3 atom pairs is important for accurate reproduction of the molecular polarizability tensor. At the same time, the use of point charges for these interactions is problematic as their spatial separation is small enough that the Coulombic approximation fails. To overcome this, the electrostatic shielding treatment proposed by Thole [30] is applied, in which the Coulomb interactions between charges / and j are modulated by a factor, S,y, as follows ... 

Mkadmh et have proposed an atom additive model to compute the static average molecular polarizabilities. First, the molecular polarizabilities of a learning set of molecules was calculated by means of the modified Thole dipole field tensor, an evolution of the point induced dipole due to Silber-stein. Values of linear screening factors were optimized to achieve minimum deviation from experimental polarizabilities and thus isotropic polarizabilities of C, H, O, N, and S were estimated in order to be applied in a simple additive model to calculate the average molecular polarizabilities of a vast number of molecules. Excellent correlations between the computed polarizability values and the experimental ones in all of the investigated groups have been achieved. 

---