The hydration of Mg and Zn is examined using molecular dynamics simulations using three computational approaches of increasing complexity: the CHARMM non-polarizable force field based on the TIP3P water model, the Drude polarizable force field based on the SWM4-NDP water model, and a combined QM/MM approach in which the inner coordination sphere is represented using a high quality density funct...

Structural properties of large NO(3)(-).(H(2)O)(n) (n = 15-500) clusters are studied by Monte Carlo simulations using effective fragment potentials (EFPs) and by classical molecular dynamics simulations using a polarizable empirical force field. The simulation results are analyzed with a focus on the description of hydrogen bonding and solvation in the clusters. In addition, a comparison betwee...

Linear response and variational treatment are formulated for Hartree-Fock (HF) and Kohn-Sham density functional theory (DFT) methods and combined discrete-continuum solvation models that incorporate self-consistently induced dipoles and charges. Due to the variational treatment, analytic nuclear gradients can be evaluated efficiently for these discrete and continuum solvation models. The forces...

Statistical thermodynamics provides a powerful theoretical framework for analyzing, understanding and predicting the conformational properties of biomolecules. The central quantity is the potential of mean force or effective energy as a function of conformation, which consists of the intramolecular energy and the solvation free energy. The intramolecular energy can be reasonably described by mo...

We propose a predictive Density Functional Theory (DFT) for the calculation of solvation free energies. Our approach is based on Helmholtz free-energy functional that consistent with perturbed-chain SAFT (PC-SAFT) equation state. This allows coarse-grained description solvent, an inhomogeneous density PC-SAFT segments. The solute, other hand, described in full detail by atomistic Lennard-Jones ...

The hydrophobic effect, i.e., the poor solvation of nonpolar parts of molecules, plays a key role in protein folding and more generally for molecular self-assembly and aggregation in aqueous media. The perturbation of the water structure accounts for many aspects of protein hydrophobicity. However, to what extent the dispersion interaction between molecular entities themselves contributes has r...

A global optimization method is described for identifying the global minimum energy conformation, as well as lower and upper bounds on the global minimum conformer of solvated peptides. Potential energy contributions are calculated using the ECEPP/3 force eld model. In considering the eeects of hydration, two implicit free energy models are compared. One method is based on the calculation of so...

Increasingly complex schemes for representing solvent effects in an implicit fashion are being used in computational analyses of biological macromolecules. These schemes speed up the calculations by orders of magnitude and are assumed to compromise little on essential features of the solvation phenomenon. In this work we examine this assumption. Five implicit solvation models, a surface area-ba...

Integral equation theory of molecular liquids based on statistical mechanics is quite promising as an essential part of multiscalemethodology for chemical and biomolecular nanosystems in solution. Beginningwith amolecular interaction potential force field, it uses diagrammatic analysis of the solvation free energy to derive integral equations for correlation functions between molecules in solut...