Thermochemical cycles that involve pKa, gas-phase acidities, aqueous solvation free energies of neutral species, and gas-phase clustering free energies have been used with the cluster pair approximation to determine the absolute aqueous solvation free energy of the proton. The best value obtained in this work is in good agreement with the value reported by Tissandier et al. (Tissandier, M. D.; ...

A coherent framework is presented for determining the free energy change accompanying ligand binding to protein receptors. The most important new feature of the method is the contribution of the flexibility of the free ligand, and hence its conformational change on binding, to the free energy. Flexibility introduces two additional terms in the free energy difference: the internal energy differe...

The Gibbs free energy of solvation and dissociation of hydrogen chloride in water is calculated through a combined molecular simulation/quantum chemical approach at four temperatures between T = 300 and 450 K. The Gibbs free energy is first decomposed into the sum of two components: the Gibbs free energy of transfer of molecular HCl from the vapor to the aqueous liquid phase and the standard-st...

: In this work, different levels of theory containing HF, B3LYP, and MP2 with different basis sets such as 6-31G, 6-31G*, 6-311G, 6-311+G, 6-31+G*, 6-31+G are used to predict relative acidity constants of some aniline derivatives. Three different kinds of radii containing UAHF, Bondi, and Pauling are used to study how cavity forms change acidity constants. In all cases, DPCM model is used to si...

Some of the Adamantane properties were calculated in this study. Chemical shift, free energy ofsolvation, free energy of cavity formation, Henry's law constant, and other properties ofAdamantane in dry phase, three solvents and three temperatures have been calculated with Abinitio method base on density functional theory (DFT) at B3lyp/6-31g, B31yp/6-31g*, B3lyp/6-31+g* and B3lyp/6-31++g** leve...

A density functional theory (DFT) protocol for the calculation of redox potentials of copper complexes is developed based on 13 model copper complexes. The redox potentials are calculated in terms of Gibbs free energy change of the redox reaction at the theory level of CAM-B3LYP/6-31+G(d,p)/SMD, with the overall Gibbs free energy change being partitioned into the Gibbs free energy change of the...

This study is about Complexes of Li doped silicon carbide nanotube with Thymine and Cytosine ingas phase and aqueous solutions. Li doped silicon carbide nanotube and its pyrimidine nucleobasecompounds were first modeled by Quantum mechanical calculations in gas phase and in water.Calculated binding energies indicated the stronger ability of thymine to functionalize silicon carbidenanotube than ...

We develop a linear response theory of solvation of ionic and dipolar solutes in anisotropic, axially symmetric polar solvents. The theory is applied to solvation in polar nematic liquid crystals. The formal theory constructs the solvation response function from projections of the solvent dipolar susceptibility on rotational invariants. These projections are obtained from Monte Carlo simulation...

In an implicit-solvent description of the solvation of charged molecules (solutes), the electrostatic free energy is a functional of concentrations of ions in the solvent. The charge density is determined by such concentrations together with the point charges of the solute atoms, and the electrostatic potential is determined by the Poisson equation with a variable dielectric coefficient. Such a...

: in this work, different levels of theory containing hf, b3lyp, and mp2 with different basis sets such as 6-31g, 6-31g*, 6-311g, 6-311+g, 6-31+g*, 6-31+g are used to predict relative acidity constants of some aniline derivatives. three different kinds of radii containing uahf, bondi, and pauling are used to study how cavity forms change acidity constants. in all cases, dpcm model is used to si...