A way to compare experimental and SCRF electronic static dipole polarizability of pure liquids

When the polarizability tensor is computed through Self-Consistent Reaction Field Models (the interactions between solute and solvent are incorporated into calculation), there still exists a need to take into account the modifications of the applied macroscopic fields at the local site of the solvated molecule (the phenomenon historically indicated as 'local field effects'). Another way is to remove local field factors from experimental mean polarizability ((alpha) over bar) and polarizability anisotropy (Deltaalpha) values. The present paper focuses on this way. Seven liquids (CS2, C6H6, (CH3)(2)CO, CHCl3, CH2Cl2, CH3CN, CCl4) have been studied. In a first step, the alpha tensor components have been computed at the B3LYP and HF levels with Sadlej basis set using a finite field procedure. The solvent effect is introduced into the calculation through the Self-Consistent Isodensity Polarizable Continuum Model (SCIPCM). In a second step, experimental literature values of refractive index, density, isothermal compressibility coefficient and depolarization ratio have been carefully chosen and introduced in modified experimental equations (where local field factors have been removed) to determine (alpha) over bar and Deltaalpha. Concerning (alpha) over bar, there is a good agreement between experimental and B3LYP values for dipolar molecules. In the case of non-dipolar molecules calculated values are always lower than experimental ones. Such a behaviour had not been observed in a previous study concerning molecules in the gas state. therefore it seems that the SCIPCM induces a deficiency over calculated (alpha) over bar (0) in the case of non-dipolar molecules. (C) 2003 Elsevier Science B.V. All rights reserved.