Polarizable Continuum Model (PCM) analysis has been carried out using B3LYP method with 6-311++G(d,p) basis set for three water soluble vitamins (biotin, L-ascorbic acid and pyridoxine) and one fat soluble vitamin (phylloquinone) in ten solvents with wide range of dielectric constants. In this paper, we report electrostatic, dispersion and repulsive interaction components of Gibb’s free energy ...

The Polarizable Continuum Model (PCM) can be used in conjunction with Density Functional Theory (DFT) and its time-dependent extension (TDDFT) to simulate the electronic and optical properties of molecules and nanoparticles immersed in a dielectric environment, typically liquid solvents. In this contribution, we develop a methodology to account for solvation effects in real-space (and real-time...

A dielectric continuum theory for the solvation of a polar molecule in a polar, polarizable solvent is tested using computer simulations of formaldehyde in water. Many classes of experiments, for example those which measure solvent-shifted vertical transition energies or electron transfer rates, require an explicit consideration of the solvent electronic polarization. Due to the computational c...

We present quantum chemical estimates of ligand-binding affinities performed, for the first time, at a level of theory for which there is a hope that dispersion and polarization effects are properly accounted for (MP2/cc-pVTZ) and at the same time effects of solvation, entropy, and sampling are included. We have studied the binding of seven biotin analogues to the avidin tetramer. The calculati...

Density Functional Theory (DFT) calculations have been carried out using a Polarizable Continuum Model (PCM) in an attempt to investigate the electro-molecular properties of branched-chain glucoside (C14C10-D-glucoside) isomers. The results showed that αconfiguration of pyranoside form is thermodynamically the most stable, while the solution should contain much more β...

An ab initio study of the addition of successive water molecules to the amino acid l-alanine in both the nonionized (N) and zwitterionic (Z) forms are presented. The main focus is the number of waters needed to stabilize the Z form and how the solvent affects conformational preference. The solvent is modeled by ab initio electronic structure theory, the EFP (effective fragment potential) model,...

Glutamine--a popular nutritional supplement, non-toxic amino acid, and an essential interorgan and intercellular ammonia transporter--can destroy the neurons' mitochondria. When glutamine enters (like a Trojan horse) into the mitochondria, in the presence of glutaminase, it reacts with water and yields glutamate and excess ammonia which opens gates in the membrane of the mitochondria and thereb...

The first implementation of a wavelet discretization of the Integral Equation Formalism (IEF) for the Polarizable Continuum Model (PCM) is presented here. The method is based on the application of a general purpose wavelet solver on the cavity boundary to solve the integral equations of the IEF-PCM problem. Wavelet methods provide attractive properties for the solution of the electrostatic prob...

A nearly linear scaling implementation of coupled-cluster with singles and doubles excitations (CCSD) can be achieved by means the domain-based local pair natural orbital (DLPNO) method. The combination DLPNO-CCSD implicit solvation methods allows calculation accurate energies chemical properties solvated systems at an affordable computational cost. We have efficiently implemented different sch...