UAHF PCM

For all PCM-UAHF calculations, the number of initial tesserae/atomic sphere has been set to 60 by default. For comparative purposes, C-PCM calculations of the... 

Schuurmann, G., Cossi, M., Barone, V., and Tomasi, J., Prediction of the pKa of carboxylic acids using the ab initio continuum-solvation model PCM-UAHF, J. Phys. Chem. A, 102, 6706-6712, 1998. 

Over the last years, the basic concepts embedded within the SCRF formalism have undergone some significant improvements, and there are several commonly used variants on this idea. To exemplify the different methods and how their results differ, one recent work from this group [52] considered the sensitivity of results to the particular variant chosen. Due to its dependence upon only the dipole moment of the solute, the older approach is referred to herein as the dipole variant. The dipole method is also crude in the sense that the solute is placed in a spherical cavity within the solute medium, not a very realistic shape in most cases. The polarizable continuum method (PCM) [53,54,55] embeds the solute in a cavity that more accurately mimics the shape of the molecule, created by a series of overlapping spheres. The reaction field is represented by an apparent surface charge approach. The standard PCM approach utilizes an integral equation formulation (IEF) [56,57], A variant of this method is the conductor-polarized continuum model (CPCM) [58] wherein the apparent charges distributed on the cavity surface are such that the total electrostatic potential cancels on the surface. The self-consistent isodensity PCM procedure [59] determines the cavity self-consistently from an isodensity surface. The UAHF (United Atom model for Hartree-Fock/6-31 G ) definition [60] was used for the construction of the solute cavity. 

Using mPWlPW/6-31G(d) and the UAHF atomic radii in Gaussian. Using B3LYP/6-31G(d) and conductor-PCM in GAMESS. 

Solvent effects on the structures and on the magnetic properties have been evaluated by using the PCM, [23] which is based on a self-consistent description of a molecule embedded in a cavity surrounded by an infinite dielectric. In order to describe the actual molecular shape in a realistic way, the cavity is defined in terms of spheres centered on non-hydrogen atoms with radii optimized following the UAHF model, [23b] which provides values of solvation free energy of hydration of many neutral and charged solutes in excellent agreement with the experimental results. 

AGj , j,(aq), of the MOx isomers syn and anti) and transition state structure (TS) obtained with QM calculation with PCM-UAHF(HF/6-31G(d)) and with TPT in the MC simulations... 

All values are in kcal/mol, and the deviations are the statistical error. The population of the anti-isomer in water is reported in the parenthesis Obtained with PCM-UAHF(B3LYP/aug-cc-pVDZ)... 

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