Self-consistent reaction field theory of solvent effects

Tapia, O.; Goscinski, Osvaldo

doi:10.1080/00268977500101461

Cited by 530 publications

(182 citation statements)

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“…Obviously, adding the average potential is an old idea that was implicitly implemented in the QM/Langevin Dipole (QM/LD) model [29][30][31] . It is also implemented implicitly in continuum models [32][33][34][35] . Furthermore, an averaging approach was implemented recently in an instructive work of Yang and coworkers 26 .…”

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confidence: 99%

Accelerating QM/MM Free Energy Calculations: Representing the Surroundings by an Updated Mean Charge Distribution

et al. 2008

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Reliable studies of enzymatic reactions by combined quantum mechanical /molecular mechanics (QM(ai)/MM) approaches, with an ab initio description of the quantum region, presents a major challenge to computational chemists. The main problem is the need for very large computer time to evaluate the QM energy, which in turn makes it extremely challenging to perform proper configurational sampling. One of the most obvious options for accelerating QM/MM simulations is the use of an average solvent potential. In fact the idea of using an average solvent potential is rather obvious and has implicitly been used in Langevin dipole / QM calculations. However, in the case of explicit solvent models the practical implementations are more challenging and the accuracy of the averaging approach has not been validated. The present study introduces the average effect of the fluctuating solvent charges by using equivalent charge distributions, which are updated every m steps. Several models are evaluated in terms of the resulting accuracy and efficiency. The most effective model divides the system into an inner region with N explicit solvent atoms and an external region with two effective charges. Different models are considered in terms of the division of the solvent system and the update frequency. Another key element of our approach is the use of the free energy perturbation (FEP) and/or linear response approximation (LRA) treatments that guarantees the evaluation of the rigorous solvation free energy. Special attention is paid to the convergence of the calculated solvation free energies and the corresponding solute polarization. The performance of the method is examined by evaluating the solvation of a water molecule and a formate ion in water and also the dipole moment of water in water solution. Remarkably, it is found that different averaging procedures eventually converge to the same value but some protocols provide optimal ways of obtaining the final QM(ai)/MM converged results. The current method can provide computational time saving of 1000 for properly converging simulations relative to calculations that evaluate the QM(ai)/MM energy every time step. A specialized version of our approach that starts with a classical FEP charging and then evaluates the free energy of moving from the classical potential to the QM/ MM potential appears to be particularly effective. This approach should provide a very powerful tool for QM(ai)/MM evaluation of solvation free energies in aqueous solutions and proteins.

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confidence: 99%

Accelerating QM/MM Free Energy Calculations: Representing the Surroundings by an Updated Mean Charge Distribution

et al. 2008

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“…If the dielectric constant was larger than 1.0, this repulsion would be smaller, and the Zn-S bond lengths would decrease. A popular method to account in an average way for an increased dielectric constant is the cavity reaction field approach (Tapia & Goscinski, 1975, Mikkelsen et al, 1988). This technique is well suited for the present model system, since [Zn(HS) 4 ] 2-fits well into a spherical cavity with little uncertainty in the location of the origin.…”

Section: Geometry Optimisations In a Dielectric Cavitymentioning

confidence: 99%

“…Reaction field calculations (Tapia & Goscinski, 1975, Mikkelsen et al, 1988 were performed by placing [Zn(HS) 4 ] 2-in a spherical cavity (radius r 0 ), surrounded by a dielectric medium with a dielectric constant, e. The charge distribution of the ligand sphere introduces an electric field acting on the dielectric medium. This reaction field interacts with the charge distribution of the ligand sphere and perturbs the one-electron Hamiltonian.…”

Section: Geometry Optimisations In a Dielectric Cavitymentioning

confidence: 99%

The coordination chemistry of the structural zinc ion in alcohol dehydrogenase studied by ab initio quantum chemical calculations

Ryde

1996

Eur Biophys J

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The coordination chemistry of the structural zinc ion in alcohol dehydrogenase studied by ab initio quantum chemical calculations General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal shown that all the four cysteine ligands are deprotonated in the enzyme, not only two of them as has been suggested. The Zn-S bond lengths are very sensitive to the theoretical treatment; in vacuum they are predicted to be 15 pm longer than in the crystal structure.Half of this discrepancy is due to electronic correlation, the rest can be attributed to screening of the negative sulphide charges by the enzyme, in particular by N-H … S hydrogen bonds. The potential surface is rather flat, so the large difference in geometry between the crystal and the vacuum structure corresponds to an energy change of less than 35 kJ/mole. The crystal bond lengths can be reproduced only with methods that accounts explicitly for the enzyme. A dielectric continuum model gives too long bond lengths, indicating that the enzyme solvates the coordination sphere better than water. Thus, the structural zinc ion can be used as a sensitive test of methods trying to model the surrounding medium in quantum chemical computations.3

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“…[26][27][28][29][30][31][32] and discrete [33][34][35][36] solvation models. When the solvent is modeled by a dielectric continuum, its effect on the molecular properties of the solute can be calculated using high-level quantum mechanical methods.…”

Section: Introductionmentioning

confidence: 99%

The isotropic nuclear magnetic shielding constants of acetone in supercritical water: A sequential Monte Carlo/quantum mechanics study including solute polarization

Fonseca

Coutinho²,

Canuto³

2008

The Journal of Chemical Physics

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Monte Carlo simulation strategies for computing the wetting properties of fluids at geometrically rough surfaces J. Chem. Phys. 135, 184702 (2011) Semi-bottom-up coarse graining of water based on microscopic simulations J. Chem. Phys. 135, 184101 (2011) Hydrophobic interactions in presence of osmolytes urea and trimethylamine-N-oxide J. Chem. Phys. 135, 174501 (2011) Potential of mean force between identical charged nanoparticles immersed in a size-asymmetric monovalent electrolyte J. Chem. Phys. 135, 164705 (2011) Additional information on J. Chem. Phys. The nuclear isotropic shielding constants ͑ 17 O͒ and ͑ 13 C͒ of the carbonyl bond of acetone in water at supercritical ͑P = 340.2 atm and T = 673 K͒ and normal water conditions have been studied theoretically using Monte Carlo simulation and quantum mechanics calculations based on the B3LYP/ 6-311+ + G͑2d ,2p͒ method. Statistically uncorrelated configurations have been obtained from Monte Carlo simulations with unpolarized and in-solution polarized solute. The results show that solvent effects on the shielding constants have a significant contribution of the electrostatic interactions and that quantitative estimates for solvent shifts of shielding constants can be obtained modeling the water molecules by point charges ͑electrostatic embedding͒. In supercritical water, there is a decrease in the magnitude of ͑ 13 C͒ but a sizable increase in the magnitude of ͑ 17 O͒ when compared with the results obtained in normal water. It is found that the influence of the solute polarization is mild in the supercritical regime but it is particularly important for ͑ 17 O͒ in normal water and its shielding effect reflects the increase in the average number of hydrogen bonds between acetone and water. Changing the solvent environment from normal to supercritical water condition, the B3LYP/ 6-311+ + G͑2d ,2p͒ calculations on the statistically uncorrelated configurations sampled from the Monte Carlo simulation give a 13 C chemical shift of 11.7Ϯ 0.6 ppm for polarized acetone in good agreement with the experimentally inferred result of 9 -11 ppm.

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Self-consistent reaction field theory of solvent effects

Cited by 530 publications

References 13 publications

Accelerating QM/MM Free Energy Calculations: Representing the Surroundings by an Updated Mean Charge Distribution

Accelerating QM/MM Free Energy Calculations: Representing the Surroundings by an Updated Mean Charge Distribution

The coordination chemistry of the structural zinc ion in alcohol dehydrogenase studied by ab initio quantum chemical calculations

The isotropic nuclear magnetic shielding constants of acetone in supercritical water: A sequential Monte Carlo/quantum mechanics study including solute polarization

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