The “good,“ the “bad,“ and the “hidden“ in neutron scattering and molecular dynamics of ionic aqueous solutions

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F22%3A00557831" target="_blank" >RIV/61388963:_____/22:00557831 - isvavai.cz</a>

Alternative codes found

RIV/60076658:12310/22:43904841

Result on the web

<a href="https://doi.org/10.1063/5.0093643" target="_blank" >https://doi.org/10.1063/5.0093643</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/5.0093643" target="_blank" >10.1063/5.0093643</a>

Result language

angličtina

Original language name

The “good,“ the “bad,“ and the “hidden“ in neutron scattering and molecular dynamics of ionic aqueous solutions

Original language description

We characterize a concentrated 7.3 m CaCl2 solution, combining neutron diffraction with chloride isotopic substitution (Cl-NDIS) in null water and molecular dynamics (MD) simulations. We elucidate the solution structure, thermodynamic properties, and extent of ion pairing previously suggested as concentration-dependent and often not observed at lower concentrations. Our Cl-NDIS measurements designate the solvent-shared ion pairing as dominant and the contact ion pairing (CIP) as insignificant even under conditions close to the solubility limit. The MD models parameterized against neutron diffraction with calcium isotopic substitution (Ca-NDIS) overestimate CIP despite successfully reproducing most of the Cl-NDIS signal. This drawback originates from the fact that Ca2+-Cl- interactions were primarily “hidden “ in the Ca-NDIS signal due to overlapping with Ca2+-O-w and Ca2+-H-w contributions to the total scattering. Contrary, MD models with moderate CIP and possessing generally good performance at high concentrations fail to reproduce the NDIS measurements accurately. Therefore, the electronic polarization, introduced in most of the recent MD models via scaling ionic charges, resolves some but not all parameterization drawbacks. We conclude that despite improving the quality of MD models “on average, “ the question “which model is the best “ has not been answered but replaced by the question “which model is better for a given research. “ An overall “good “ model can still be inappropriate or, in some instances, “bad “ and, unfortunately, produce erroneous results. The accurate interpretation of several NDIS datasets, complemented by MD simulations, can prevent such mistakes and help identify the strengths, weaknesses, and convenient applications for corresponding computational models.& nbsp,Published under an exclusive license by AIP Publishing.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10403 - Physical chemistry

Project

<a href="/en/project/LTAUSA17163" target="_blank" >LTAUSA17163: Molecular simulations of processes at solid-liquid interfaces</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Chemical Physics

ISSN

0021-9606

e-ISSN

1089-7690

Volume of the periodical

156

Issue of the periodical within the volume

19

Country of publishing house

US - UNITED STATES

Number of pages

11

Pages from-to

194505

UT code for WoS article

000797901200003

EID of the result in the Scopus database

2-s2.0-85130694088