On the validity of the Stokes–Einstein relation for various water force fields

Tsimpanogiannis, Ioannis N.; Jamali, Seyed Hossein; Economou, Ioannis G.; Vlugt, Thijs J. H.; Moultos, Othonas A.

doi:10.1080/00268976.2019.1702729

Cited by 25 publications

(26 citation statements)

References 68 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This data also greatly resembles previous observations on water. [101,103] This two-regime decoupling behavior is not normally apparent in liquids exhibiting 'ordinary' glass-formation, where the anomalies in the thermodynamic response functions at the l-transition discussed below are also not observed.…”

Section: B Quantification Of Fragile-to-strong Glass-formationmentioning

confidence: 88%

Dynamic heterogeneity, cooperative motion, and Johari–Goldstein $$\beta $$-relaxation in a metallic glass-forming material exhibiting a fragile-to-strong transition

Zhang

Wang

et al. 2021

Eur. Phys. J. E

View full text Add to dashboard Cite

We investigate the Johari-Goldstein (JG) b-relaxation process in a model metallic glass-forming (GF) material (Al90Sm10), previously studied extensively by both frequency-dependent mechanical measurements and simulation studies devoted to equilibrium properties, by molecular dynamics simulations based on validated and optimized interatomic potentials with the primary aim of better understanding the nature of this universal relaxation process from a dynamic heterogeneity (DH) perspective. The present relatively low temperature and long-time simulations reveal a direct correspondence between the JG b-relaxation time tJG and the lifetime of the mobile particle clusters tM, defined as in previous DH studies, a relationship dual to the corresponding previously observed relationship between the a-relaxation time ta and the lifetime of immobile particle clusters tIM. Moreover, we find that the average diffusion coefficient D nearly coincides with DAl, of the smaller atomic species (Al), and that the hopping time associated with D coincides with tJG to within numerical uncertainty, both trends being in accord with experimental studies indicating that the JG b-relaxation is dominated by the smaller atomic species and the observation of a direct relation between this relaxation process and rate of molecular diffusion in GF materials at low temperatures where the JG b-relaxation becomes the prevalent mode of structural relaxation. As an unanticipated aspect of our study, we find that Al90Sm10 exhibits fragile-to-strong (FS) glassformation, as found in measurements of many other metallic GF liquids, but this fact does not greatly alter the nature of DH in this material and the relation of DH to dynamical properties. 10

show abstract

Section: B Quantification Of Fragile-to-strong Glass-formationmentioning

confidence: 88%

Dynamic heterogeneity, cooperative motion, and Johari–Goldstein $$\beta $$-relaxation in a metallic glass-forming material exhibiting a fragile-to-strong transition

Zhang

Wang

et al. 2021

Eur. Phys. J. E

View full text Add to dashboard Cite

show abstract

“…6000 molecules [143]). Based on the YH correction (Equation (1)), and by assuming that the self-diffusivity of a molecule, with effective hydrodynamic radius R, can be described using the Stokes-Einstein equation [14,31,144]…”

Section: Finite-size Dependence Of Self-diffusivitiesmentioning

confidence: 99%

Finite-size effects of diffusion coefficients computed from molecular dynamics: a review of what we have learned so far

Celebi

Jamali

Bardow

et al. 2020

Molecular Simulation

Self Cite

108

View full text Add to dashboard Cite

The number of molecules used in a typical Molecular Dynamics (MD) simulations is orders of magnitude lower than in the thermodynamic limit. It is therefore essential to correct diffusivities computed from Molecular Dynamics simulations for finite-size effects. We present a comprehensive review on finitesize effects of diffusion coefficients by considering self-, Maxwell-Stefan, and Fick diffusion coefficients in pure liquids, as well as binary, ternary, and quaternary mixtures. All finite-size corrections, both analytical and empirical, are discussed in detail. The finite-size effects of rotational and confined diffusion are also briefly discussed.

show abstract

“…In the past decade, several studies have shown that force field based molecular dynamics (MD) simulations can provide molecular level insight into the inclusion complex formation, and predict experimentally measured binding constants reasonably well [33] , [34] , [35] , [36] , [37] , [38] . MD simulations are also widely used to calculate transport properties in aqueous solutions [39] , [40] , [41] , [42] , [43] , [44] , [45] , [46] , [47] . To the best of our knowledge, there are only two studies reporting diffusion coefficients of CDs calculated using MD simulations to date.…”

Section: Introductionmentioning

confidence: 99%

Diffusivity of α-, β-, γ-cyclodextrin and the inclusion complex of β-cyclodextrin: Ibuprofen in aqueous solutions; A molecular dynamics simulation study

Erdős

Frangou

Vlugt

et al. 2021

Fluid Phase Equilibria

Self Cite

View full text Add to dashboard Cite

Cyclodextrins (CDs) are widely used in drug delivery, catalysis, food and separation processes. In this work, a comprehensive simulation study on the diffusion of the native α -, β - and γ -CDs in aqueous solutions is carried out using Molecular Dynamics simulations. The effect of the system size on the computed self-diffusivity is investigated and it is found that the required correction can be as much as 75% of the final value. The effect of the water force field is examined and it is shown that the q4md-CD/TIP4P/2005 force field combination predicts the experimentally measured self-diffusion coefficients of CDs very accurately. The self-diffusion coefficients of the three native CDs were also computed in aqueous-NaCl solutions using the Joung and Cheatham (JC) and the Madrid-2019 force fields. It is found that Na ions have higher affinity towards the CDs when the JC force field is used and for this reason the predicted diffusivity of CDs is lower compared to simulations using the Madrid-2019 force field. As a model system for drug delivery and waste-water treatment applications, the diffusion of the β -CD:Ibuprofen inclusion complex in water is studied. In agreement with experiments for similar components, it is shown that the inclusion complex and the free β -CD have almost equal self-diffusion coefficients. Our analysis revealed that this is most likely caused by the almost full inclusion of the ibuprofen in the cavity of the β -CD. Our findings show that Molecular Dynamics simulation can be used to provide reasonable diffusivity predictions, and to obtain molecular-level understanding useful for industrial applications of CDs.

show abstract

On the validity of the Stokes–Einstein relation for various water force fields

Cited by 25 publications

References 68 publications

Dynamic heterogeneity, cooperative motion, and Johari–Goldstein $$\beta $$-relaxation in a metallic glass-forming material exhibiting a fragile-to-strong transition

Dynamic heterogeneity, cooperative motion, and Johari–Goldstein $$\beta $$-relaxation in a metallic glass-forming material exhibiting a fragile-to-strong transition

Finite-size effects of diffusion coefficients computed from molecular dynamics: a review of what we have learned so far

Diffusivity of α-, β-, γ-cyclodextrin and the inclusion complex of β-cyclodextrin: Ibuprofen in aqueous solutions; A molecular dynamics simulation study

Contact Info

Product

Resources

About