It is shown how a dynamical theory for proton transfer rates in solution can be implemented molecular-dynamics simulation model reaction system. The the nonadiabatic limit, which occurs via quantum tunneling of proton. importance coupling to solvent and an intramolecular vibration illustrated, results are successfully compared with analytic rate-constant expressions several limiting regimes.

A Landau−Zener curve crossing formulation is developed for proton transfer rate constants over the range of coupling. This approach spans weak coupling regime, where a nonadiabatic tunneling, to strong at reaction transition state motion quantized vibration lying above barrier in coordinate. The theory requires that there solute surrounding polar solvent and includes influence vibrational heavy particles between which transfers. Analytic formulas are given various limits strength frequency...

In order to study the microscopic nature of hydrated proton and its transport mechanism, we have introduced a multi-state empirical valence bond model, fitted ab-initio results [J. Phys. Chem. B 102, 4261 (1998) references therein]. The model makes it possible take into account an arbitrary number N states for system proton+water electronic ground-state is obtained by diagonalization N×N interaction matrix. resulting force field was applied study, at low computational cost, structure...

A theoretical approach exploiting molecular dynamics simulations to treat adiabatic proton transfer between an acid AH and a base B in polar, aprotic solvent is presented. The of the transfer, which occurs on electronic ground state surface reactive hydrogen-bonded complex AH...B, strongly influenced by interaction reaction system with AB stretch vibration. fully incorporates quantum character motion as well that vibration yields mechanistic picture for thermally activated polar solvent....

For mixed quantum-classical molecular dynamics simulations of solvated excess charges a novel and efficient method to expand the solute electronic wave function in distributed Gaussian basis with shell structure is presented. The aggregate orbitals capable mimicking shape fluctuation charge distribution its diffusion through solvent. This approach also offers an easy pathway treat solvent polarization explicit self-consistent fashion. As applications, results adiabatic for hydrated electron...

A molecular-dynamics study of a model for AH−B⇄A−−H+B reactions in liquid chloromethane is presented. The parameters the are fitted to those typical OH–N proton-transfer complexes. rate constant computed at quantum level complexes various H-bond strength and A-B equilibrium distance. influence properties complex on mechanism outlined. Also static dynamical role solvent, tunneling contribution rate, associated kinetic isotope effect discussed. calculations based two independent methods. First...

We study, by an adiabatic dynamical simulation technique, a mixed classical-quantum model for strongly H-bonded complexes in polar solvents. The solvent influence on the proton dynamics is interpreted terms of protonic polarization effect, usually referred to as Zundel polarization. relation solvent-induced transfer and consequences broadening infrared absorption spectrum are discussed. show that increasing solvent-complex coupling, system passes from ‘‘oscillatory’’ ‘‘reactive’’ behavior,...

We investigate the orientational properties of a homogeneous and inhomogeneous tetrahedral four-patch fluid (Bol–Kern–Frenkel model). Using integral equations, either (i) HNC or (ii) modified scheme with simulation input, full dependence pair direct correlation functions is determined. Density functionals for problem are constructed via two different methods. The first, molecular density functional theory, utilizes function an isotropic hard-sphere bridge functional. second method, machine...

The classical and quantum dynamics of an excess proton in water is studied by molecular simulations. electronic structure the system described extended multistate valence-bond Hamiltonian that allows for breaking formation O−H+ bonds. character treated means effective (path-integral) proton-transfer surface. Whereas simulations predict hydrated appears a mixture structures, inclusion quantization leads to prevalence . mechanism can be mostly as translocation transient across hydrogen-bond...

A new electron–water molecule pseudopotential is developed and tested in the present paper. The formal development of potential based on our earlier quantum mechanical model calculations excess electronic states electron-water system [Turi et al., J. Chem. Phys. 114, 7805 (2001)]. Although has a very simple analytical form containing only nine adjustable parameters, it reproduces exact eigenvalue state electron density smooth pseudo-wave function static-exchange limit. Of individual energy...

The density functional theory based molecular dynamics simulation method ("Car−Parrinello") was applied in a numerical study of the electronic properties, hydrogen bonding, and infrared spectroscopy trans cis isomer N-methylacetamide aqueous solution. A detailed analysis structure solvated molecules, terms localized Wannier functions Born atomic charges, is presented. Two schemes for computation solute absorption spectrum are investigated: In first determined by Fourier transforming time...

A classical density functional theory approach to solvation in molecular solvent is presented. The properties of an arbitrary solute a given solvent, both described by force field, can be obtained minimization position and orientation-dependent free-energy functional. In the homogeneous reference fluid approximation, limited two-body correlations, unknown excess term approximated angular-dependent direct correlation function pure solvent. We show that this extracted from preliminary MD...

Three-dimensional implementations of liquid-state theories offer an efficient alternative to computer simulations for the atomic-level description aqueous solutions in complex environments. In this context, we present a (classical) molecular density functional theory (MDFT) water that is derived from first principles and based on two classical fields, scalar one, particle density, vectorial multipolar polarization density. Its implementation requires as input partial charge distribution...

Reaction and relaxation processes induced by photoexcitation of an aqueous chloride ion are studied with quantum molecular dynamics simulations. A predominant channel leading to a metastable hydrated electron-chlorine pair is found. By means theoretical transient stationary absorption spectra, the solvent reorganization involved in charge repartitioning discussed. The dissipation excess electron kinetic energy surrounding water molecules plays essential role equilibration electron-atom pair....

A general method for obtaining effective normal modes of a molecular system from dynamics simulations is presented. The based on localization criterion the Fourier transformed velocity time-correlation functions modes. For given choice function used, becomes equivalent to principal mode analysis (PMA) covariance matrix diagonalization. On other hand, proper leads novel with strong analogy usual equilibrium structures, where Hessian at minimum energy structure replaced by thermal averaged...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSolvent-induced proton transfer in strongly hydrogen-bonded complexes: an adiabatic dynamical simulation studyD. Borgis, G. Tarjus, and H. AzzouzCite this: J. Phys. Chem. 1992, 96, 8, 3188–3191Publication Date (Print):April 1, 1992Publication History Published online1 May 2002Published inissue 1 April 1992https://pubs.acs.org/doi/10.1021/j100187a003https://doi.org/10.1021/j100187a003research-articleACS PublicationsRequest reuse permissionsArticle...

In order to study protein-protein nonbonded interactions, we present the development of a new reduced protein model that represents each amino acid residue with one three coarse grains, whose physical properties are derived in consistent bottom-up procedure from higher-resolution all-atom AMBER force field. The resulting potential energy function is pairwise additive and includes distinct van-der-Waals Coulombic terms. effective interactions deduced preliminary molecular dynamics simulations...

Molecular density functional theory (MDFT) offers an efficient implicit-solvent method to estimate molecule solvation free-energies, whereas conserving a fully molecular representation of the solvent. Even within second-order approximation for free-energy functional, so-called homogeneous reference fluid approximation, we show that hydration free-energies computed data set 500 organic compounds are similar quality as those obtained from dynamics perturbation simulations, with computer cost...

Solvation free energies are efficiently predicted by molecular density functional theory if one corrects the overpressure introduced usual homogeneous reference fluid approximation. Sergiievskyi et al. [J. Phys. Chem. Lett. 5, 1935-1942 (2014)] recently derived rigorous compensation of this excess pressure (referred as "pressure correction" or PC) and proposed an empirical "ideal gas" supplementary correction "advanced PC+) that further enhances calculated solvation energies. In a recent...

We describe a density functional theory approach to solvation in molecular solvents. The free energy of complex solute can be obtained by direct minimization functional, instead the thermodynamic integration scheme necessary when using atomistic simulations. In homogeneous reference fluid approximation, expression free-energy relies on knowledge correlation function pure solvent. After discussing general solvents, we present generic describing dipolar solvent and show how it reduced...