Mechanical polarizability

The quantum mechanical polarizability is calculated using the DFT, with B3P86 (Becke s three-parameter functional [53] with the non-local correlation provided by Perdew [54]). The basis set used for the water molecules is 6-311 + +G. Because of the very diffuse nature of the anion F, the basis set used is the specially designed, and very extensive, fully uncontracted 14s 9p 6d 2f Gaussian-type orbitals [55]. All the QM calculations were made with the Gaussian98 program [56]. 

The approach which will be reviewed here has been formulated within the framework of the quantum mechanical polarizable continuum model (PCM) [7], Within this method, the effective properties are introduced to connect the outcome of the quantum mechanical calculations on the solvated molecules to the outcome of the corresponding NLO experiment [8], The correspondence between the QM-PCM approach and the semi-classical approach will also be discussed in order to show similarities and differences between the two approaches. 

S. J. Mo, T. Vreven, B. Mennucci, K. Morokuma and J. Tomasi, Theoretical study of the Sn2 reaction of C1-(H20) +CH3C1 using our own n-layered integrated molecular orbitals and molecular mechanics polarizable continuum model method (ONIOM-PCM), Theor. Chem. Acc., Ill (2004) 154-161. 

In the shell model, as mentioned above, the short-range repulsion and van der Waals interactions are taken to act between the shell particles. This finding has the effect of coupling the electrostatic and steric interactions in the system in a solid-state system where the nuclei are fixed at the lattice positions, polarization can occur not only from the electric field generated by neighboring atoms, but also from the short-range interactions with close neighbors (as, e.g., in the case of defects, substitutions, or surfaces). This ability to model both electrical and mechanical polarizability is one reason for the success of shell models in solid-state ionic materials. 

F. J. Olivares del Valle and J. Tomasi, Chem. Phys., 150, 139 (1991). Electron Correlation and Solvation Effects. I. Basic Formulation and Preliminary Attempt to Include the Electron Correlation in the Quantum Mechanical Polarizable Continuum Model so as to Study Solvation Phenomena. 

Donchev, A. G., Galkin, N. G., Illarionov, A. A., Khoruzhii, 0. V., Olevanov, M. A., Ozrin, V. D., Subbotin, M. V., and Tarasov, V. I. (2006a]. Water properties from first principles Simulations by a general-purpose quantum mechanical polarizable force field, Proc. Natl. Acad. Sci. USA 103, pp, 8613-8617. 

A quantum mechanical polarizable force field for biomolecular interactions, Proc. Natl. Acad. Sci. USA 102, pp. 7829-7834. 

The Drude oscillator model has a number of advantages over other polarizable models facilitating its implementation in multiple simulation packages including CHARMM [150], NAMD [165], ChemSell QM/MM [192] and the OpenMM suite of utilities for GPU [193]. Representing a dipole as two point charges provides an intuitive physical picture in terms of displacement of the electronic distribution the model is able to represent delocalization without need of additional non-atomic sites since the dipole is not point-like as, e.g., in the induced dipole model. For example, the use of auxiliary particles allows for the inclusion of mechanical polarizabilities [194]... 

Mennucci B, CappeUi C, Cammi R, Tomasi J. A quantum mechanical polarizable continuum model for the calculation of resonance Raman spectra in condensed phase. Theor Chem Aa. 2007 117(5-6) 1029-1039. http //dx.doi.Org/10.1007/s00214-006-0221-2. 

Quantum Mechanical Polarizable Force Field (QMPFF3) Refinement and Validation of the Dispersion Interaction for Aromatic Carbon. 

A. G. Donchev, N. G. Galkin, A. A. Illarionov, O. V. Khoruzhii, M. A. Olevanov, V. D. Ozrin, M. V. Subbotin, and V. I. Tarasov, Proc. Natl. Acad. Set. U. S. A., 103(23), 8613—8617 (2006). Water Properties from First Principles Simulations by a General-Purpose Quantum Mechanical Polarizable Force Field. 

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