1
|
Ojha D, Henao A, Zysk F, Kühne TD. Nuclear quantum effects on the vibrational dynamics of the water-air interface. J Chem Phys 2024; 160:204114. [PMID: 38804494 DOI: 10.1063/5.0204071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 04/11/2024] [Indexed: 05/29/2024] Open
Abstract
We have applied path-integral molecular dynamics simulations to investigate the impact of nuclear quantum effects on the vibrational dynamics of water molecules at the water-air interface. The instantaneous fluctuations in the frequencies of the O-H stretch modes are calculated using the wavelet method of time series analysis, while the time scales of vibrational spectral diffusion are determined from frequency-time correlation functions and joint probability distributions. We find that the inclusion of nuclear quantum effects leads not only to a redshift in the vibrational frequency distribution by about 120 cm-1 for both the bulk and interfacial water molecules but also to an acceleration of the vibrational dynamics at the water-air interface by as much as 35%. In addition, a blueshift of about 45 cm-1 is seen in the vibrational frequency distribution of interfacial water molecules compared to that of the bulk. Furthermore, the dynamics of water molecules beyond the topmost molecular layer was found to be rather similar to that of bulk water.
Collapse
Affiliation(s)
- Deepak Ojha
- Dynamics of Condensed Matter and Center for Sustainable Systems Design, Department of Chemistry, University of Paderborn, Warburger Str. 100, D-33098 Paderborn, Germany
| | - Andrés Henao
- Dynamics of Condensed Matter and Center for Sustainable Systems Design, Department of Chemistry, University of Paderborn, Warburger Str. 100, D-33098 Paderborn, Germany
| | - Frederik Zysk
- Dynamics of Condensed Matter and Center for Sustainable Systems Design, Department of Chemistry, University of Paderborn, Warburger Str. 100, D-33098 Paderborn, Germany
| | - Thomas D Kühne
- Center for Advanced Systems Understanding (CASUS), Untermarkt 20, D-02826 Görlitz, Germany, Helmholtz Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, D-01328 Dresden, Germany, and TU Dresden, Institute of Artificial Intelligence, Chair of Computational System Sciences, Nöthnitzer Straße 46, D-01187 Dresden, Germany
| |
Collapse
|
2
|
Villard J, Bircher MP, Rothlisberger U. Structure and dynamics of liquid water from ab initio simulations: adding Minnesota density functionals to Jacob's ladder. Chem Sci 2024; 15:4434-4451. [PMID: 38516095 PMCID: PMC10952088 DOI: 10.1039/d3sc05828j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 02/12/2024] [Indexed: 03/23/2024] Open
Abstract
The accurate representation of the structural and dynamical properties of water is essential for simulating the unique behavior of this ubiquitous solvent. Here we assess the current status of describing liquid water using ab initio molecular dynamics, with a special focus on the performance of all the later generation Minnesota functionals. Findings are contextualized within the current knowledge on DFT for describing bulk water under ambient conditions and compared to experimental data. We find that, contrary to the prevalent idea that local and semilocal functionals overstructure water and underestimate dynamical properties, M06-L, revM06-L, and M11-L understructure water, while MN12-L and MN15-L overdistance water molecules due to weak cohesive effects. This can be attributed to a weakening of the hydrogen bond network, which leads to dynamical fingerprints that are over fast. While most of the hybrid Minnesota functionals (M06, M08-HX, M08-SO, M11, MN12-SX, and MN15) also yield understructured water, their dynamical properties generally improve over their semilocal counterparts. It emerges that exact exchange is a crucial component for accurately describing hydrogen bonds, which ultimately leads to corrections in both the dynamical and structural properties. However, an excessive amount of exact exchange strengthens hydrogen bonds and causes overstructuring and slow dynamics (M06-HF). As a compromise, M06-2X is the best performing Minnesota functional for water, and its D3 corrected variant shows very good structural agreement. From previous studies considering nuclear quantum effects (NQEs), the hybrid revPBE0-D3, and the rung-5 RPA (RPA@PBE) have been identified as the only two approximations that closely agree with experiments. Our results suggest that the M06-2X(-D3) functionals have the potential to further improve the reproduction of experimental properties when incorporating NQEs through path integral approaches. This work provides further proof that accurate modeling of water interactions requires the inclusion of both exact exchange and balanced (non-local) correlation, highlighting the need for higher rungs on Jacob's ladder to achieve predictive simulations of complex biological systems in aqueous environments.
Collapse
Affiliation(s)
- Justin Villard
- Laboratory of Computational Chemistry and Biochemistry, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL) Lausanne CH-1015 Switzerland
| | - Martin P Bircher
- Computational and Soft Matter Physics, Universität Wien Wien A-1090 Austria
| | - Ursula Rothlisberger
- Laboratory of Computational Chemistry and Biochemistry, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL) Lausanne CH-1015 Switzerland
| |
Collapse
|
3
|
Piskulich ZA, Laage D, Thompson WH. A structure-dynamics relationship enables prediction of the water hydrogen bond exchange activation energy from experimental data. Chem Sci 2024; 15:2197-2204. [PMID: 38332825 PMCID: PMC10848719 DOI: 10.1039/d3sc04495e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Accepted: 12/23/2023] [Indexed: 02/10/2024] Open
Abstract
It has long been understood that the structural features of water are determined by hydrogen bonding (H-bonding) and that the exchange of, or "jumps" between, H-bond partners underlies many of the dynamical processes in water. Despite the importance of H-bond exchanges there is, as yet, no direct method for experimentally measuring the timescale of the process or its associated activation energy. Here, we identify and exploit relationships between water's structural and dynamical properties that provide an indirect route for determining the H-bond exchange activation energy from experimental data. Specifically, we show that the enthalpy and entropy determining the radial distribution function in liquid water are linearly correlated with the activation energies for H-bond jumps, OH reorientation, and diffusion. Using temperature-dependent measurements of the radial distribution function from the literature, we demonstrate how these correlations allow us to infer the value of the jump activation energy, Ea,0, from experimental results. This analysis gives Ea,0 = 3.43 kcal mol-1, which is in good agreement with that predicted by the TIP4P/2005 water model. We also illustrate other approaches for estimating this activation energy consistent with these estimates.
Collapse
Affiliation(s)
- Zeke A Piskulich
- Department of Chemistry, University of Kansas Lawrence KS 66045 USA
| | - Damien Laage
- PASTEUR, Départment de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS Paris 75005 France
| | - Ward H Thompson
- Department of Chemistry, University of Kansas Lawrence KS 66045 USA
| |
Collapse
|
4
|
Thakur AC, Remsing RC. Nuclear quantum effects in the acetylene:ammonia plastic co-crystal. J Chem Phys 2024; 160:024502. [PMID: 38189604 DOI: 10.1063/5.0179161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 12/20/2023] [Indexed: 01/09/2024] Open
Abstract
Organic molecular solids can exhibit rich phase diagrams. In addition to structurally unique phases, translational and rotational degrees of freedom can melt at different state points, giving rise to partially disordered solid phases. The structural and dynamic disorder in these materials can have a significant impact on the physical properties of the organic solid, necessitating a thorough understanding of disorder at the atomic scale. When these disordered phases form at low temperatures, especially in crystals with light nuclei, the prediction of material properties can be complicated by the importance of nuclear quantum effects. As an example, we investigate nuclear quantum effects on the structure and dynamics of the orientationally disordered, translationally ordered plastic phase of the acetylene:ammonia (1:1) co-crystal that is expected to exist on the surface of Saturn's moon Titan. Titan's low surface temperature (∼90 K) suggests that the quantum mechanical behavior of nuclei may be important in this and other molecular solids in these environments. By using neural network potentials combined with ring polymer molecular dynamics simulations, we show that nuclear quantum effects increase orientational disorder and rotational dynamics within the acetylene:ammonia (1:1) co-crystal by weakening hydrogen bonds. Our results suggest that nuclear quantum effects are important to accurately model molecular solids and their physical properties in low-temperature environments.
Collapse
Affiliation(s)
- Atul C Thakur
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Richard C Remsing
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA
| |
Collapse
|
5
|
Ryan MJ, Yang N, Kwac K, Wilhelm KB, Chi BK, Weix DJ, Cho M, Zanni MT. The hydrogen-bonding dynamics of water to a nitrile-functionalized electrode is modulated by voltage according to ultrafast 2D IR spectroscopy. Proc Natl Acad Sci U S A 2023; 120:e2314998120. [PMID: 38127983 PMCID: PMC10756189 DOI: 10.1073/pnas.2314998120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 11/15/2023] [Indexed: 12/23/2023] Open
Abstract
We report the hydrogen-bonding dynamics of water to a nitrile-functionalized and plasmonic electrode surface as a function of applied voltage. The surface-enhanced two-dimensional infrared spectra exhibit hydrogen-bonded and non-hydrogen-bonded nitrile features in similar proportions, plus cross peaks between the two. Isotopic dilution experiments show that the cross peaks arise predominantly from chemical exchange between hydrogen-bonded and non-hydrogen-bonded nitriles. The chemical exchange rate depends upon voltage, with the hydrogen bond of the water to the nitriles breaking 2 to 3 times slower (>63 vs. 25 ps) under a positive as compared to a negative potential. Spectral diffusion created by hydrogen-bond fluctuations occurs on a ~1 ps timescale and is moderately potential-dependent. Timescales from molecular dynamics simulations agree qualitatively with the experiment and show that a negative voltage causes a small net displacement of water away from the surface. These results show that the voltage applied to an electrode can alter the timescales of solvent motion at its interface, which has implications for electrochemically driven reactions.
Collapse
Affiliation(s)
- Matthew J. Ryan
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI53706
| | - Nan Yang
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI53706
| | - Kijeong Kwac
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul02841, Republic of Korea
- Department of Chemistry, Korea University, Seoul02841, Republic of Korea
| | - Kiera B. Wilhelm
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI53706
| | - Benjamin K. Chi
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI53706
| | - Daniel J. Weix
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI53706
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul02841, Republic of Korea
- Department of Chemistry, Korea University, Seoul02841, Republic of Korea
| | - Martin T. Zanni
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI53706
| |
Collapse
|
6
|
Yang X, Liu R, Xu R, Wang Z. Sequential flipping: the donor-acceptor exchange mechanism in water trimers. Phys Chem Chem Phys 2023; 25:21957-21963. [PMID: 37553960 DOI: 10.1039/d3cp02666c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
Abstract
The donor-acceptor exchange (DAE) is a significant hydrogen bond network rearrangement (HBNR) mechanism because it can lead to the change of the hydrogen bond direction. In this work, we report a new DAE mechanism found in water trimers that is realized by sequential flipping (SF) of all molecules rather than the well-known proton transfer (PT) process. Meanwhile, the SF process has a much smaller potential barrier (0.262 eV) than the previously predicted collective rotation process (about 1.7 eV), implying that the SF process is the main flipping process that can lead to DAE. Importantly, high-precision ab initio calculations show that SF-DAE can make the water ring to show a clear chiral difference from PT-DAE, which brings the prospect of distinguishing the two confusing processes based on circular dichroism spectra. The reaction rate analysis including quantum tunneling indicates an obvious temperature-dependent competitive relationship between the SF and PT processes; specifically, the SF process dominates above 65 K, while the PT process dominates below 65 K. Therefore, in most cases, the contribution for DAE mainly comes from the flipping process, rather than the PT process as previously thought. Our work enriches the understanding of the DAE mechanism in water trimers and provides a piece of the jigsaw that has been sought for the HBNR mechanism.
Collapse
Affiliation(s)
- Xinrui Yang
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China.
| | - Rui Liu
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China.
| | - Ruiqi Xu
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China.
| | - Zhigang Wang
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China.
- International Center for Computational Method & Software, College of Physics, Jilin University, Changchun 130012, China
| |
Collapse
|
7
|
Conti Nibali V, Maiti S, Saija F, Heyden M, Cassone G. Electric-field induced entropic effects in liquid water. J Chem Phys 2023; 158:2889002. [PMID: 37154276 DOI: 10.1063/5.0139460] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 03/13/2023] [Indexed: 05/10/2023] Open
Abstract
Externally applied electric fields in liquid water can induce a plethora of effects with wide implications in electrochemistry and hydrogen-based technologies. Although some effort has been made to elucidate the thermodynamics associated with the application of electric fields in aqueous systems, to the best of our knowledge, field-induced effects on the total and local entropy of bulk water have never been presented so far. Here, we report on classical TIP4P/2005 and ab initio molecular dynamics simulations measuring entropic contributions carried by diverse field intensities in liquid water at room temperature. We find that strong fields are capable of aligning large fractions of molecular dipoles. Nevertheless, the order-maker action of the field leads to quite modest entropy reductions in classical simulations. Albeit more significant variations are recorded during first-principles simulations, the associated entropy modifications are small compared to the entropy change involved in the freezing phenomenon, even at intense fields slightly beneath the molecular dissociation threshold. This finding further corroborates the idea that electrofreezing (i.e., the electric-field-induced crystallization) cannot take place in bulk water at room temperature. In addition, here, we propose a molecular-dynamics-based analysis (3D-2PT) that spatially resolves the local entropy and the number density of bulk water under an electric field, which enables us to map their field-induced changes in the environment of reference H2O molecules. By returning detailed spatial maps of the local order, the proposed approach is capable of establishing a link between entropic and structural modifications with atomistic resolution.
Collapse
Affiliation(s)
- Valeria Conti Nibali
- Department of Mathematical and Computer Sciences, Physical Sciences and Earth Sciences, University of Messina, 98166 Messina, Italy
- Institute for Chemical-Physical Processes, National Research Council of Italy (IPCF-CNR), 98158 Messina, Italy
| | - Sthitadhi Maiti
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, USA
| | - Franz Saija
- Institute for Chemical-Physical Processes, National Research Council of Italy (IPCF-CNR), 98158 Messina, Italy
| | - Matthias Heyden
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, USA
| | - Giuseppe Cassone
- Institute for Chemical-Physical Processes, National Research Council of Italy (IPCF-CNR), 98158 Messina, Italy
| |
Collapse
|
8
|
Chatterjee S, Chowdhury T, Bagchi S. Does variation in composition affect dynamics when approaching the eutectic composition? J Chem Phys 2023; 158:114203. [PMID: 36948840 DOI: 10.1063/5.0139153] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Abstract
Deep eutectic solvent is a mixture of two or more components, mixed in a certain molar ratio, such that the mixture melts at a temperature lower than individual substances. In this work, we have used a combination of ultrafast vibrational spectroscopy and molecular dynamics simulations to investigate the microscopic structure and dynamics of a deep eutectic solvent (1:2 choline chloride: ethylene glycol) at and around the eutectic composition. In particular, we have compared the spectral diffusion and orientational relaxation dynamics of these systems with varying compositions. Our results show that although the time-averaged solvent structures around a dissolved solute are comparable across compositions, both the solvent fluctuations and solute reorientation dynamics show distinct differences. We show that these subtle changes in solute and solvent dynamics with changing compositions arise from the variations in the fluctuations of the different intercomponent hydrogen bonds.
Collapse
Affiliation(s)
- Srijan Chatterjee
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008, India
| | - Tubai Chowdhury
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008, India
| | - Sayan Bagchi
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008, India
| |
Collapse
|
9
|
Méndez E, Videla PE, Laria D. Collective Proton Transfers in Cyclic Water-Ammonia Tetramers: A Path Integral Machine-Learning Study. J Phys Chem A 2023; 127:1839-1848. [PMID: 36794937 DOI: 10.1021/acs.jpca.2c07994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
We present results from machine-learning-based path integral molecular dynamics simulations that describe isomerization paths articulated via collective proton transfers along mixed, cyclic tetramers combining water and ammonia at cryogenic conditions. The net result of such isomerizations is a reverse of the chirality of the global hydrogen-bonding architecture along the different cyclic moieties. In monocomponent tetramers, the classical free energy profiles associated with these isomerizations present the usual symmetric double-well characteristics whereas the reactive paths exhibit full concertedness among the different intermolecular transfer processes. Contrastingly, in mixed water/ammonia tetramers, the incorporation of a second component introduces imbalances in the strengths of the different hydrogen bonds leading to a partial loss of concertedness, most notably at the vicinity of the transition state. As such, the highest and lowest degrees of progression are registered along OH···N and O···HN coordinations, respectively. These characteristics lead to polarized transition state scenarios akin to solvent-separated ion-pair configurations. The explicit incorporation of nuclear quantum effects promotes drastic depletions in the activation free energies and modifications in the overall shape of the profiles which include central plateau-like stages, indicating the prevalence of deep tunneling regimes. On the other hand, the quantum treatment of the nuclei partially restores the degree of concertedness among the evolutions of the individual transfers.
Collapse
Affiliation(s)
- Emilio Méndez
- Departamento de Química Inorgánica, Analítica y Química-Física and INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires Ciudad Universitaria, Pabellón II, 1428 Buenos Aires, Argentina
| | - Pablo E Videla
- Department of Chemistry and Energy Sciences Institute, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Daniel Laria
- Departamento de Química Inorgánica, Analítica y Química-Física and INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires Ciudad Universitaria, Pabellón II, 1428 Buenos Aires, Argentina.,Departamento de Física de la Materia Condensada, Comisión Nacional de Energía Atómica, Avenida Libertador 8250, 1429 Buenos Aires, Argentina
| |
Collapse
|
10
|
Kurapothula PJ, Shepherd S, Wilkins DM. Competing Nuclear Quantum Effects and Hydrogen-Bond Jumps in Hydrated Kaolinite. J Phys Chem Lett 2023; 14:1542-1547. [PMID: 36745462 PMCID: PMC9940297 DOI: 10.1021/acs.jpclett.2c03896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 02/01/2023] [Indexed: 06/18/2023]
Abstract
Recent work has shown that the dynamics of hydrogen bonds in pure clays are affected by nuclear quantum fluctuations, with different effects for the hydrogen bonds holding different layers of the clay together and for those within the same layer. At the clay-water interface there is an even wider range of types of hydrogen bond, suggesting that the quantum effects may be yet more varied. We apply classical and thermostated ring polymer molecular dynamics simulations to show that nuclear quantum effects accelerate hydrogen-bond dynamics to varying degrees. By interpreting the results in terms of the extended jump model of hydrogen-bond switching, we can understand the origins of these effects in terms of changes in the quantum kinetic energy of hydrogen atoms during an exchange. We also show that the extended jump mechanism is applicable not only to the hydrogen bonds involving water, but also those internal to the clay.
Collapse
|
11
|
Daru J, Forbert H, Behler J, Marx D. Coupled Cluster Molecular Dynamics of Condensed Phase Systems Enabled by Machine Learning Potentials: Liquid Water Benchmark. PHYSICAL REVIEW LETTERS 2022; 129:226001. [PMID: 36493459 DOI: 10.1103/physrevlett.129.226001] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 09/05/2022] [Accepted: 10/05/2022] [Indexed: 06/17/2023]
Abstract
Coupled cluster theory is a general and systematic electronic structure method, but in particular the highly accurate "gold standard" coupled cluster singles, doubles and perturbative triples, CCSD(T), can only be applied to small systems. To overcome this limitation, we introduce a framework to transfer CCSD(T) accuracy of finite molecular clusters to extended condensed phase systems using a high-dimensional neural network potential. This approach, which is automated, allows one to perform high-quality coupled cluster molecular dynamics, CCMD, as we demonstrate for liquid water including nuclear quantum effects. The machine learning strategy is very efficient, generic, can be systematically improved, and is applicable to a variety of complex systems.
Collapse
Affiliation(s)
- János Daru
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Harald Forbert
- Center for Solvation Science ZEMOS, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Jörg Behler
- Universität Göttingen, Institut für Physikalische Chemie, Theoretische Chemie, Tammannstrasse 6, 37077 Göttingen, Germany
| | - Dominik Marx
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
| |
Collapse
|
12
|
Pluhařová E, Stirnemann G, Laage D. On water reorientation dynamics in cation hydration shells. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
13
|
Thomsen B, Shiga M. Structures of liquid and aqueous water isotopologues at ambient temperature from ab initio path integral simulations. Phys Chem Chem Phys 2022; 24:10851-10859. [PMID: 35504275 DOI: 10.1039/d2cp00499b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The heavy hydrogen isotopes D and T are found in trace amounts in water, and when their concentration increases they can play an intricate role in modulating the physical properties of the liquid. We present an analysis of the microscopic structures of ambient light water (H2O(l)), heavy water (D2O(l)), T2O(l), HDO(aq) and HTO(aq) studied by ab initio path integral molecular dynamics (PIMD). Unlike previous ab initio PIMD investigations of H2O(l) and D2O(l) [Chen et al., Phys. Rev. Lett., 2003, 91, 215503] [Machida et al., J. Chem. Phys., 2017, 148, 102324] we find that D2O(l) is more structured than H2O(l), as is predicted by the experiment. The agreement between the experiment and our simulation for H2O(l) and D2O(l) allows us to accurately predict the intra- and intermolecular structures of T2O(l) HDO(aq) and HTO(aq). T2O(l) is found to have a similar intermolecular structure to that of D2O(l), while the intramolecular structure is more compact, giving rise to a smaller dipole moment than those of H2O(l) and D2O(l). For the mixed isotope species, HDO(aq) and HTO(aq), we find smaller dipole moments and fewer hydrogen bonds when compared with the pure species H2O and D2O. We can attribute this effect to the relative compactness of the mixed isotope species, which results in a lower dipole moment than that of the pure species.
Collapse
Affiliation(s)
- Bo Thomsen
- CCSE, Japan Atomic Energy Agency, 178-4-4, Wakashiba, Kashiwa, Chiba, 277-0871, Japan.
| | - Motoyuki Shiga
- CCSE, Japan Atomic Energy Agency, 178-4-4, Wakashiba, Kashiwa, Chiba, 277-0871, Japan.
| |
Collapse
|
14
|
Thomsen B, Shiga M. Ab initio study of nuclear quantum effects on sub- and supercritical water. J Chem Phys 2021; 155:194107. [PMID: 34800944 DOI: 10.1063/5.0071857] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The structures of water in the ambient, subcritical, and supercritical conditions at various densities were studied systematically by ab initio path integral molecular dynamics simulations. It was found that the nuclear quantum effects (NQEs) have a significant impact on the structure of hydrogen bonds in close contact, not only in the ambient condition but also in the sub- and supercritical conditions. The NQEs on the structure beyond the hydrogen bond contact are important in ambient water, but not much for water in the sub- and supercritical conditions. The NQEs are furthermore important for determining the number of hydrogen bonds in the ambient conditions, and this role is, however, diminished in the sub- and supercritical conditions. The NQEs do, nevertheless, show their importance in determining the intramolecular structure of water and the close contact structures of the hydrogen bonds, even at sub- and supercritical conditions. Using the RPBE-D3 functional, the computed radial distribution functions for ambient water are in excellent agreement with experimental data, upgrading our previous results using the BLYP-D2 functional [Machida et al., J. Chem. Phys. 148, 102324 (2018)]. The computed radial distribution functions for water in the sub- and supercritical conditions were carefully compared with experiment. In particular, we found that the first peak in hydrogen pair distribution functions matches only when the NQEs are taken into account.
Collapse
Affiliation(s)
- Bo Thomsen
- CCSE, Japan Atomic Energy Agency, 178-4-4, Wakashiba, Kashiwa, Chiba 277-0871, Japan
| | - Motoyuki Shiga
- CCSE, Japan Atomic Energy Agency, 178-4-4, Wakashiba, Kashiwa, Chiba 277-0871, Japan
| |
Collapse
|
15
|
Shepherd S, Lan J, Wilkins DM, Kapil V. Efficient Quantum Vibrational Spectroscopy of Water with High-Order Path Integrals: From Bulk to Interfaces. J Phys Chem Lett 2021; 12:9108-9114. [PMID: 34523941 DOI: 10.1021/acs.jpclett.1c02574] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Vibrational spectroscopy is key in probing the interplay between the structure and dynamics of aqueous systems. To map different regions of experimental spectra to the microscopic structure of a system, it is important to combine them with first-principles atomistic simulations that incorporate the quantum nature of nuclei. Here we show that the large cost of calculating the quantum vibrational spectra of aqueous systems can be dramatically reduced compared with standard path integral methods by using approximate quantum dynamics based on high-order path integrals. Together with state-of-the-art machine-learned electronic properties, our approach gives an excellent description not only of the infrared and Raman spectra of bulk water but also of the 2D correlation and the more challenging sum-frequency generation spectra of the water-air interface. This paves the way for understanding complex interfaces such as water encapsulated between or in contact with hydrophobic and hydrophilic materials through robust and inexpensive surface-sensitive and multidimensional spectra with first-principles accuracy.
Collapse
Affiliation(s)
- Sam Shepherd
- Atomistic Simulation Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, United Kingdom
| | - Jinggang Lan
- Department of Chemistry, University of Zürich, Zürich 8057, Switzerland
| | - David M Wilkins
- Atomistic Simulation Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, United Kingdom
| | - Venkat Kapil
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW,United Kingdom
| |
Collapse
|
16
|
Roget SA, Piskulich ZA, Thompson WH, Fayer MD. Identical Water Dynamics in Acrylamide Hydrogels, Polymers, and Monomers in Solution: Ultrafast IR Spectroscopy and Molecular Dynamics Simulations. J Am Chem Soc 2021; 143:14855-14868. [PMID: 34491037 DOI: 10.1021/jacs.1c07151] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The dynamics and structure of water in polyacrylamide hydrogels (PAAm-HG), polyacrylamide, and acrylamide solutions are investigated using ultrafast infrared experiments on the OD stretch of dilute HOD/H2O and molecular dynamics simulations. The amide moiety of the monomer/polymers interacts strongly with water through hydrogen bonding (H-bonding). The FT-IR spectra of the three systems indicate that the range of H-bond strengths is relatively unchanged from bulk water. Vibrational population relaxation measurements show that the amide/water H-bonds are somewhat weaker but fall within the range of water/water H-bond strengths. A previous study of water dynamics in PAAm-HG suggested that the slowing observed was due to increasing confinement with concentration. Here, for the same concentrations of the amide moiety, the experimental results demonstrate that the reorientational dynamics (infrared pump-probe experiments) and structural dynamics (two-dimensional infrared spectroscopy) are identical in the three acrylamide systems studied. Molecular dynamics simulations of the water orientational relaxation in aqueous solutions of the acrylamide monomer, trimer, and pentamer are in good agreement with the experimental results and are essentially chain length independent. The simulations show that there is a slower, low-amplitude (<7%) decay component not accessible by the experiments. The simulations examine the dynamics and structure of water H-bonded to acrylamide, in the first solvent shell, and beyond for acrylamide monomers and short chains. The experiments and simulations show that the slowing of water dynamics in PAAm-HG is not caused by confinement in the polymer network but rather by interactions with individual acrylamide moieties.
Collapse
Affiliation(s)
- Sean A Roget
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Zeke A Piskulich
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Ward H Thompson
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Michael D Fayer
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| |
Collapse
|
17
|
Drużbicki K, Gaboardi M, Fernandez-Alonso F. Dynamics & Spectroscopy with Neutrons-Recent Developments & Emerging Opportunities. Polymers (Basel) 2021; 13:1440. [PMID: 33947108 PMCID: PMC8125526 DOI: 10.3390/polym13091440] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 04/27/2021] [Indexed: 12/19/2022] Open
Abstract
This work provides an up-to-date overview of recent developments in neutron spectroscopic techniques and associated computational tools to interrogate the structural properties and dynamical behavior of complex and disordered materials, with a focus on those of a soft and polymeric nature. These have and continue to pave the way for new scientific opportunities simply thought unthinkable not so long ago, and have particularly benefited from advances in high-resolution, broadband techniques spanning energy transfers from the meV to the eV. Topical areas include the identification and robust assignment of low-energy modes underpinning functionality in soft solids and supramolecular frameworks, or the quantification in the laboratory of hitherto unexplored nuclear quantum effects dictating thermodynamic properties. In addition to novel classes of materials, we also discuss recent discoveries around water and its phase diagram, which continue to surprise us. All throughout, emphasis is placed on linking these ongoing and exciting experimental and computational developments to specific scientific questions in the context of the discovery of new materials for sustainable technologies.
Collapse
Affiliation(s)
- Kacper Drużbicki
- Materials Physics Center, CSIC-UPV/EHU, Paseo Manuel de Lardizabal 5, 20018 Donostia-San Sebastian, Spain;
- Polish Academy of Sciences, Center of Molecular and Macromolecular Studies, Sienkiewicza 112, 90-363 Lodz, Poland
| | - Mattia Gaboardi
- Elettra—Sincrotrone Trieste S.C.p.A., S.S. 14 km 163.5 in Area Science Park, 34149 Trieste, Italy;
| | - Felix Fernandez-Alonso
- Materials Physics Center, CSIC-UPV/EHU, Paseo Manuel de Lardizabal 5, 20018 Donostia-San Sebastian, Spain;
- Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastian, Spain
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
- IKERBASQUE, Basque Foundation for Science, Plaza Euskadi 5, 48009 Bilbao, Spain
| |
Collapse
|
18
|
Piskulich ZA, Laage D, Thompson WH. On the role of hydrogen-bond exchanges in the spectral diffusion of water. J Chem Phys 2021; 154:064501. [PMID: 33588543 DOI: 10.1063/5.0041270] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The dynamics of a vibrational frequency in a condensed phase environment, i.e., the spectral diffusion, has attracted considerable interest over the last two decades. A significant impetus has been the development of two-dimensional infrared (2D-IR) photon-echo spectroscopy that represents a direct experimental probe of spectral diffusion, as measured by the frequency-frequency time correlation function (FFCF). In isotopically dilute water, which is perhaps the most thoroughly studied system, the standard interpretation of the longest timescale observed in the FFCF is that it is associated with hydrogen-bond exchange dynamics. Here, we investigate this connection by detailed analysis of both the spectral diffusion timescales and their associated activation energies. The latter are obtained from the recently developed fluctuation theory for the dynamics approach. The results show that the longest timescale of spectral diffusion obtained by the typical analysis used cannot be directly associated with hydrogen-bond exchanges. The hydrogen-bond exchange time does appear in the decay of the water FFCF, but only as an additional, small-amplitude (<3%) timescale. The dominant contribution to the long-time spectral diffusion dynamics is considerably shorter than the hydrogen-bond exchange time and exhibits a significantly smaller activation energy. It thus arises from hydrogen-bond rearrangements, which occur in between successful hydrogen-bond partner exchanges, and particularly from hydrogen bonds that transiently break before returning to the same acceptor.
Collapse
Affiliation(s)
- Zeke A Piskulich
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
| | - Damien Laage
- PASTEUR, Department of Chemistry, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France
| | - Ward H Thompson
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
| |
Collapse
|
19
|
Rey R, Hynes JT. Solvation Dynamics in Water. 4. On the Initial Regime of Solvation Relaxation. J Phys Chem B 2020; 124:7668-7681. [PMID: 32790403 DOI: 10.1021/acs.jpcb.0c05706] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It is shown, by means of numerical and analytic work, that initial molecular momenta play little significant role in the initial fast solvation relaxation that follows electronic excitation of, and charge creation for, a standard model system of a solute in water. Instead, the nonequilibrium dynamics are predominantly described by noninertial "steering" by the torques directly generated by the newly created charge distribution. It is this process that largely overcomes inertia and drives the relaxation dynamics on a time scale of a few tens of femtoseconds in the key initial regime of the dynamics. These results are discussed in the context of commonly employed descriptions such as inertial, Gaussian, and underdamped dynamical behavior.
Collapse
Affiliation(s)
- Rossend Rey
- Departament de Fı́sica, Universitat Politècnica de Catalunya, Campus Nord B4-B5, Barcelona 08034, Spain
| | - James T Hynes
- PASTEUR, Department of Chemistry, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France.,Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| |
Collapse
|
20
|
Wang L, Ceriotti M, Markland TE. Quantum kinetic energy and isotope fractionation in aqueous ionic solutions. Phys Chem Chem Phys 2020; 22:10490-10499. [PMID: 31942581 DOI: 10.1039/c9cp06483d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
At room temperature, the quantum contribution to the kinetic energy of a water molecule exceeds the classical contribution by an order of magnitude. The quantum kinetic energy (QKE) of a water molecule is modulated by its local chemical environment and leads to uneven partitioning of isotopes between different phases in thermal equilibrium, which would not occur if the nuclei behaved classically. In this work, we use ab initio path integral simulations to show that QKEs of the water molecules and the equilibrium isotope fractionation ratios of the oxygen and hydrogen isotopes are sensitive probes of the hydrogen bonding structures in aqueous ionic solutions. In particular, we demonstrate how the QKE of water molecules in path integral simulations can be decomposed into translational, rotational and vibrational degrees of freedom, and use them to determine the impact of solvation on different molecular motions. By analyzing the QKEs and isotope fractionation ratios, we show how the addition of the Na+, Cl- and HPO42- ions perturbs the competition between quantum effects in liquid water and impacts their local solvation structures.
Collapse
Affiliation(s)
- Lu Wang
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA.
| | | | | |
Collapse
|
21
|
Chizallet C. Toward the Atomic Scale Simulation of Intricate Acidic Aluminosilicate Catalysts. ACS Catal 2020. [DOI: 10.1021/acscatal.0c01136] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Céline Chizallet
- IFP Energies nouvelles Solaize, Rond-Point de l’Echangeur de Solaize, BP 3, 69360 Solaize, France
| |
Collapse
|
22
|
Tao X, Shushkov P, Miller TF. Microcanonical rates from ring-polymer molecular dynamics: Direct-shooting, stationary-phase, and maximum-entropy approaches. J Chem Phys 2020; 152:124117. [DOI: 10.1063/1.5144307] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Xuecheng Tao
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
| | - Philip Shushkov
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
| | - Thomas F. Miller
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
| |
Collapse
|
23
|
Zhang Y, Stirnemann G, Hynes JT, Laage D. Water dynamics at electrified graphene interfaces: a jump model perspective. Phys Chem Chem Phys 2020; 22:10581-10591. [PMID: 32149294 DOI: 10.1039/d0cp00359j] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reorientation dynamics of water at electrified graphene interfaces was recently shown [J. Phys. Chem. Lett., 2020, 11, 624-631] to exhibit a surprising and strongly asymmetric behavior: positive electrode potentials slow down interfacial water reorientation, while for increasingly negative potentials water dynamics first accelerates before reaching an extremum and then being retarded for larger potentials. Here we use classical molecular dynamics simulations to determine the molecular mechanisms governing water dynamics at electrified interfaces. We show that changes in water reorientation dynamics with electrode potential arise from the electrified interfaces' impacts on water hydrogen-bond jump exchanges, and can be quantitatively described by the extended jump model. Finally, our simulations indicate that no significant dynamical heterogeneity occurs within the water interfacial layer next to the weakly interacting graphene electrode.
Collapse
Affiliation(s)
- Yiwei Zhang
- PASTEUR, Department of Chemistry, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France.
| | | | | | | |
Collapse
|
24
|
Zhang Y, de Aguiar HB, Hynes JT, Laage D. Water Structure, Dynamics, and Sum-Frequency Generation Spectra at Electrified Graphene Interfaces. J Phys Chem Lett 2020; 11:624-631. [PMID: 31899643 DOI: 10.1021/acs.jpclett.9b02924] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The properties of water at an electrified graphene electrode are studied via classical molecular dynamics simulations with a constant potential approach. We show that the value of the applied electrode potential has dramatic effects on the structure and dynamics of interfacial water molecules. While a positive potential slows down the reorientational and translational dynamics of water, an increasing negative potential first accelerates the interfacial water dynamics before a deceleration at very large magnitude potential values. Further, our spectroscopic calculations indicate that the water rearrangements induced by electrified interfaces can be probed experimentally. In particular, the calculated water vibrational sum-frequency generation (SFG) spectra show that SFG specifically reports on the first two water layers at 0 V but that at larger magnitude applied potentials the resulting static field induces long-range contributions to the spectrum. Electrified graphene interfaces provide promising paradigm systems for comprehending both short- and long-range neighboring aqueous system impacts.
Collapse
Affiliation(s)
- Yiwei Zhang
- PASTEUR, Department of Chemistry , École normale Supérieure, PSL University, Sorbonne Université, CNRS , 75005 Paris , France
| | - Hilton B de Aguiar
- Département de Physique , École normale supérieure, PSL University, CNRS , 24 rue Lhomond , 75005 Paris , France
| | - James T Hynes
- PASTEUR, Department of Chemistry , École normale Supérieure, PSL University, Sorbonne Université, CNRS , 75005 Paris , France
- Department of Chemistry , University of Colorado , Boulder , Colorado 80309 , United States
| | - Damien Laage
- PASTEUR, Department of Chemistry , École normale Supérieure, PSL University, Sorbonne Université, CNRS , 75005 Paris , France
| |
Collapse
|
25
|
Wexler AD, Fuchs EC, Woisetschläger J, Vitiello G. Electrically induced liquid-liquid phase transition in water at room temperature. Phys Chem Chem Phys 2019; 21:18541-18550. [PMID: 31397450 DOI: 10.1039/c9cp03192h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In this work we expand on findings previously reported [Wexler et al., Phys. Chem. Chem. Phys., 2016, 18, 16281] on the experimental observation of a phase transition in a hydrogen bonded liquid manifesting in long range dipole-dipole interactions. The studied system, liquid water stressed by an electric field, exhibits collective oscillations brought about through spontaneous breakdown of symmetry. Raman spectroscopy identifies the primary excitation of the emergent phase as transverse optically active phonon-like sidebands that appear on the hydrogen bonded asymmetric stretch mode. The phase transition is observed throughout the entire volume of liquid. The system also exhibits a self-similarity relation between the scattered Raman intensity and the electric field strength which further supports the conclusion that collective behavior persists against thermal disruption. The experimental findings are discussed in terms of a quantum field theory for macroscopic quantum systems.
Collapse
Affiliation(s)
- Adam D Wexler
- Arie Zwijnenburg Laboratory for Advanced Microscopy and Optical Metrology, Wetsus - European Center of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911MA Leeuwarden, The Netherlands.
| | | | | | | |
Collapse
|
26
|
Laage D, Stirnemann G. Effect of Ions on Water Dynamics in Dilute and Concentrated Aqueous Salt Solutions. J Phys Chem B 2019; 123:3312-3324. [DOI: 10.1021/acs.jpcb.9b01053] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Damien Laage
- PASTEUR, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France
| | - Guillaume Stirnemann
- CNRS Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique, PSL University, Sorbonne Paris Cité, 13 rue Pierre et Marie Curie, 75005 Paris, France
| |
Collapse
|
27
|
Affiliation(s)
- Wei Fang
- School of Physics and Collaborative Innovation Centre of Quantum Matter, Peking University, Beijing, People's Republic of China
- Thomas Young Centre, London Centre for Nanotechnology, and Department of Physics and Astronomy, University College London, London, UK
- Laboratory of Physical Chemistry, ETH Zurich, Zurich, Switzerland
| | - Ji Chen
- Department of Electronic Structure Theory, Max Plank Institute for Solid State Research, Stuttgart, Germany
| | - Yexin Feng
- School of Physics and Electronics, Hunan University, Changsha, People's Republic of China
| | - Xin-Zheng Li
- School of Physics and Collaborative Innovation Centre of Quantum Matter, Peking University, Beijing, People's Republic of China
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Peking University, Beijing, People's Republic of China
| | - Angelos Michaelides
- Thomas Young Centre, London Centre for Nanotechnology, and Department of Physics and Astronomy, University College London, London, UK
| |
Collapse
|
28
|
Pluhařová E, Jungwirth P, Matubayasi N, Marsalek O. Structure and Dynamics of the Hydration Shell: Spatially Decomposed Time Correlation Approach. J Chem Theory Comput 2019; 15:803-812. [PMID: 30537825 DOI: 10.1021/acs.jctc.8b00111] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecular simulations provide insight into solvation structures and dynamics with unparalleled spatial and temporal resolution. Here, we take advantage of this fact and develop a set of generally applicable computational tools for a detailed analysis of the hydration shell around an ionic or molecular solute. These tools allow us to quantify and visualize orientationally resolved radial distribution functions as well as distance-resolved orientational time-correlation functions of water molecules surrounding the solute. Such a detailed view of the hydration shells allows us to unravel important structural and dynamical features, which are not accessible when employing standard analysis techniques.
Collapse
Affiliation(s)
- Eva Pluhařová
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , Dolejškova 2155/3 , 18223 Prague 8 , Czech Republic
| | - Pavel Jungwirth
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences , Flemingovo nám. 2 , 16610 Prague 6 , Czech Republic
| | - Nobuyuki Matubayasi
- Division of Chemical Engineering, Graduate School of Engineering Science , Osaka University , Toyonaka, Osaka 560-8531 , Japan.,Elements Strategy Initiative for Catalysts and Batteries , Kyoto University , Katsura, Kyoto 615-8520 , Japan
| | - Ondrej Marsalek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences , Flemingovo nám. 2 , 16610 Prague 6 , Czech Republic.,Charles University , Faculty of Mathematics and Physics , Ke Karlovu 3 , 12116 Prague 2 , Czech Republic
| |
Collapse
|
29
|
Suvitha A, Venkataramanan NS, Sahara R, Kawazoe Y. A theoretical exploration of the intermolecular interactions between resveratrol and water: a DFT and AIM analysis. J Mol Model 2019; 25:56. [DOI: 10.1007/s00894-019-3941-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 01/24/2019] [Indexed: 12/27/2022]
|
30
|
Impact of nuclear quantum effects on the structural inhomogeneity of liquid water. Proc Natl Acad Sci U S A 2019; 116:2458-2463. [PMID: 30692247 DOI: 10.1073/pnas.1818182116] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The 2D Raman-terahertz (THz) response of liquid water is studied in dependence of temperature and isotope substitution ([Formula: see text]O, [Formula: see text]O, and [Formula: see text]O). In either case, a very short-lived (i.e., between 75 and 95 fs) echo is observed that reports on the inhomogeneity of the low-frequency intermolecular modes and hence, on the heterogeneity of the hydrogen bond networks of water. The echo lifetime slows down by about 20% when cooling the liquid from room temperature to the freezing point. Furthermore, the echo lifetime of [Formula: see text]O is [Formula: see text] slower than that of [Formula: see text]O, and both can be mapped on each other by introducing an effective temperature shift of [Formula: see text] K. In contrast, the temperature-dependent echo lifetimes of [Formula: see text]O and [Formula: see text]O are the same within error. [Formula: see text]O and [Formula: see text]O have identical masses, yet [Formula: see text]O is much closer to [Formula: see text]O in terms of nuclear quantum effects. It is, therefore, concluded that the echo is a measure of the structural inhomogeneity of liquid water induced by nuclear quantum effects.
Collapse
|
31
|
Gregorovič A, Apih T, Žagar V, Seliger J. 14N NQR spectroscopy reveals the proton position in N–H⋯N bonds: a case study with proton sponges. Phys Chem Chem Phys 2019; 21:306-313. [DOI: 10.1039/c8cp05183f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The position of the proton in intramolecular N–H⋯N hydrogen bonds has been determined to a high accuracy with 14N Nuclear Quadrupole Resonance (NQR) spectroscopy.
Collapse
Affiliation(s)
| | - Tomaž Apih
- Institute “Jožef Stefan”
- 1000 Ljubljana
- Slovenia
| | | | - Janez Seliger
- Institute “Jožef Stefan”
- 1000 Ljubljana
- Slovenia
- Faculty of Mathematics and Physics
- University of Ljubljana
| |
Collapse
|
32
|
Piskulich ZA, Thompson WH. The activation energy for water reorientation differs between IR pump-probe and NMR measurements. J Chem Phys 2018; 149:164504. [DOI: 10.1063/1.5050203] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Zeke A. Piskulich
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
- Center for Environmentally Beneficial Catalysis, University of Kansas, Lawrence, Kansas 66047, USA
| | - Ward H. Thompson
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
- Center for Environmentally Beneficial Catalysis, University of Kansas, Lawrence, Kansas 66047, USA
| |
Collapse
|
33
|
Hellström M, Ceriotti M, Behler J. Nuclear Quantum Effects in Sodium Hydroxide Solutions from Neural Network Molecular Dynamics Simulations. J Phys Chem B 2018; 122:10158-10171. [DOI: 10.1021/acs.jpcb.8b06433] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Matti Hellström
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
- Universität Göttingen, Institut für Physikalische Chemie, Theoretische Chemie, Tammannstr. 6, 37077 Göttingen, Germany
| | - Michele Ceriotti
- Laboratory of Computational Science and Modeling, Institute of Materials, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Jörg Behler
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
- Universität Göttingen, Institut für Physikalische Chemie, Theoretische Chemie, Tammannstr. 6, 37077 Göttingen, Germany
| |
Collapse
|
34
|
|
35
|
Cole WTS, Yönder Ö, Sheikh AA, Fellers RS, Viant MR, Saykally RJ, Farrell JD, Wales DJ. Terahertz VRT Spectroscopy of the Water Hexamer-h12 Cage: Dramatic Libration-Induced Enhancement of Hydrogen Bond Tunneling Dynamics. J Phys Chem A 2018; 122:7421-7426. [PMID: 30148958 DOI: 10.1021/acs.jpca.8b05777] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the assignment and analysis of 176 transitions belonging to a librational band of the (H2O)6 cage isomer near 525 cm-1(15 THz). From a fit of the transitions to an asymmetric top model, we observe both dramatic changes in the rotational constants relative to the ground state, indicating significant nonrigidity, and striking enhancement in the tunneling motions that break and reform the hydrogen bonds in the cluster. This is the fifth water cluster system to display such an enhancement in the 15 THz librational region, the details of which may help to elucidate the hydrogen bond dynamics occurring in bulk liquid water.
Collapse
Affiliation(s)
- William T S Cole
- Department of Chemistry , University of California , Berkeley , California 94720 , United States
| | - Özlem Yönder
- Department of Chemistry , University of California , Berkeley , California 94720 , United States.,Lehrstuhl für Theoretische Chemie , Ruhr-Universität Bochum , D-44780 Bochum , North Rhine-Westphalia Germany
| | - Akber A Sheikh
- Department of Chemistry , University of California , Berkeley , California 94720 , United States
| | - Raymond S Fellers
- Department of Chemistry , University of California , Berkeley , California 94720 , United States
| | - Mark R Viant
- Department of Chemistry , University of California , Berkeley , California 94720 , United States
| | - Richard J Saykally
- Department of Chemistry , University of California , Berkeley , California 94720 , United States
| | - James D Farrell
- CAS Key Laboratory of Soft Matter Physics, Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China
| | - David J Wales
- CAS Key Laboratory of Soft Matter Physics, Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China.,Department of Chemistry , University of Cambridge , Cambridge CB2 1EW , U.K
| |
Collapse
|
36
|
Zhang W, Chen X, van Duin ACT. Isotope Effects in Water: Differences of Structure, Dynamics, Spectrum, and Proton Transport between Heavy and Light Water from ReaxFF Reactive Force Field Simulations. J Phys Chem Lett 2018; 9:5445-5452. [PMID: 30188129 DOI: 10.1021/acs.jpclett.8b02379] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Investigating properties of both heavy and light water at the atomistic level is essential to understanding chemical and biological processes in aqueous solution. However, appropriately describing their difference on the nanoscale is still challenging. Employing ReaxFF reactive molecular dynamics simulations, we systematically study the structure, dynamics, and spectra of heavy and light water. With the water force field potential we developed, the different features between heavy and light water can be simulated appropriately by the classical treatment on large size and time scale. Here, we also report the structural difference between D3O+ and H3O+ in bulk heavy/light water. In addition, the diffusion constants of heavy and light water are successfully reproduced, and the Grotthuss hopping mechanism of proton transport in liquid water is properly described as well. It allows us to study a complex system in heavy/light aqueous environments, such as proton transport, chemical reaction, and tracing the reaction mechanism with an isotope substitute.
Collapse
Affiliation(s)
- Weiwei Zhang
- Department of Mechanical and Nuclear Engineering , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Xing Chen
- Department of Chemistry , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Adri C T van Duin
- Department of Mechanical and Nuclear Engineering , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| |
Collapse
|
37
|
Gehrke S, Hollóczki O. Hydrogen Bonding of N‐Heterocyclic Carbenes in Solution: Mechanisms of Solvent Reorganization. Chemistry 2018; 24:11594-11604. [DOI: 10.1002/chem.201802286] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 06/07/2018] [Indexed: 11/05/2022]
Affiliation(s)
- Sascha Gehrke
- Mulliken Center for Theoretical ChemistryUniversity of Bonn Beringstr. 4+6 53115 Bonn Germany
- Max Planck Institute for Chemical Energy Conversion Stiftstrasse 34-36 45470 Muelheim an der Ruhr Germany
| | - Oldamur Hollóczki
- Mulliken Center for Theoretical ChemistryUniversity of Bonn Beringstr. 4+6 53115 Bonn Germany
| |
Collapse
|
38
|
Litman Y, Donadio D, Ceriotti M, Rossi M. Decisive role of nuclear quantum effects on surface mediated water dissociation at finite temperature. J Chem Phys 2018; 148:102320. [PMID: 29544260 DOI: 10.1063/1.5002537] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Water molecules adsorbed on inorganic substrates play an important role in several technological applications. In the presence of light atoms in adsorbates, nuclear quantum effects (NQEs) influence the structural stability and the dynamical properties of these systems. In this work, we explore the impact of NQEs on the dissociation of water wires on stepped Pt(221) surfaces. By performing ab initio molecular dynamics simulations with van der Waals corrected density functional theory, we note that several competing minima for both intact and dissociated structures are accessible at finite temperatures, making it important to assess whether harmonic estimates of the quantum free energy are sufficient to determine the relative stability of the different states. We thus perform ab initio path integral molecular dynamics (PIMD) in order to calculate these contributions taking into account the conformational entropy and anharmonicities at finite temperatures. We propose that when adsorption is weak and NQEs on the substrate are negligible, PIMD simulations can be performed through a simple partition of the system, resulting in considerable computational savings. We then calculate the full contribution of NQEs to the free energies, including also anharmonic terms. We find that they result in an increase of up to 20% of the quantum contribution to the dissociation free energy compared with the harmonic estimates. We also find that the dissociation process has a negligible contribution from tunneling but is dominated by zero point energies, which can enhance the rate of dissociation by three orders of magnitude. Finally we highlight how both temperature and NQEs indirectly impact dipoles and the redistribution of electron density, causing work function changes of up to 0.4 eV with respect to static estimates. This quantitative determination of the change in the work function provides a possible approach to determine experimentally the most stable configurations of water oligomers on the stepped surfaces.
Collapse
Affiliation(s)
- Yair Litman
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - Davide Donadio
- Department of Chemistry, University of California Davis, One Shields Ave., Davis, California 95616, USA
| | - Michele Ceriotti
- Laboratory of Computational Science and Modelling, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Mariana Rossi
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| |
Collapse
|
39
|
Smith B, Akimov AV. Entangled trajectories Hamiltonian dynamics for treating quantum nuclear effects. J Chem Phys 2018; 148:144106. [DOI: 10.1063/1.5022573] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Brendan Smith
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260-3000, USA
| | - Alexey V. Akimov
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260-3000, USA
| |
Collapse
|
40
|
Cyran JD, Backus EHG, Nagata Y, Bonn M. Structure from Dynamics: Vibrational Dynamics of Interfacial Water as a Probe of Aqueous Heterogeneity. J Phys Chem B 2018; 122:3667-3679. [PMID: 29490138 PMCID: PMC5900549 DOI: 10.1021/acs.jpcb.7b10574] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
The structural heterogeneity of water
at various interfaces can be revealed by time-resolved sum-frequency
generation spectroscopy. The vibrational dynamics of the O–H
stretch vibration of interfacial water can reflect structural variations.
Specifically, the vibrational lifetime is typically found to increase
with increasing frequency of the O–H stretch vibration, which
can report on the hydrogen-bonding heterogeneity of water. We compare
and contrast vibrational dynamics of water in contact with various
surfaces, including vapor, biomolecules, and solid interfaces. The
results reveal that variations in the vibrational lifetime with vibrational
frequency are very typical, and can frequently be accounted for by
the bulk-like heterogeneous response of interfacial water. Specific
interfaces exist, however, for which the behavior is less straightforward.
These insights into the heterogeneity of interfacial water thus obtained
contribute to a better understanding of complex phenomena taking place
at aqueous interfaces, such as photocatalytic reactions and protein
folding.
Collapse
Affiliation(s)
- Jenée D Cyran
- Max Planck Institute for Polymer Research , Ackermannweg 10 , 55128 Mainz , Germany
| | - Ellen H G Backus
- Max Planck Institute for Polymer Research , Ackermannweg 10 , 55128 Mainz , Germany
| | - Yuki Nagata
- Max Planck Institute for Polymer Research , Ackermannweg 10 , 55128 Mainz , Germany
| | - Mischa Bonn
- Max Planck Institute for Polymer Research , Ackermannweg 10 , 55128 Mainz , Germany
| |
Collapse
|
41
|
Machida M, Kato K, Shiga M. Nuclear quantum effects of light and heavy water studied by all-electron first principles path integral simulations. J Chem Phys 2018; 148:102324. [DOI: 10.1063/1.5000091] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Affiliation(s)
- Masahiko Machida
- CCSE, Japan Atomic Energy Agency (JAEA), 178-4-4, Wakashiba, Kashiwa, Chiba 277-0871, Japan
| | - Koichiro Kato
- Mizuho Information and Research Institute, Inc., 2-3, Kandanishiki-cho, Chiyoda-ku, Tokyo 101-8443, Japan
| | - Motoyuki Shiga
- CCSE, Japan Atomic Energy Agency (JAEA), 178-4-4, Wakashiba, Kashiwa, Chiba 277-0871, Japan
| |
Collapse
|
42
|
Ojha D, Henao A, Kühne TD. Nuclear quantum effects on the vibrational dynamics of liquid water. J Chem Phys 2018; 148:102328. [PMID: 29544291 DOI: 10.1063/1.5005500] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Based on quantum-mechanical path-integral molecular dynamics simulations, the impact of nuclear quantum effects on the vibrational and hydrogen bond dynamics in liquid water is investigated. The instantaneous fluctuations in the frequencies of the O-H stretch modes are calculated using the wavelet method of time-series analysis, while the time scales of the vibrational spectral diffusion are determined from frequency-time correlation functions, joint probability distributions, and the slope of three-pulse photon echo. We find that the inclusion of nuclear quantum effects leads not only to a redshift of the vibrational frequency distribution by around 130 cm-1 but also to an acceleration of the vibrational dynamics by as much as 30%. In addition, quantum fluctuations also entail a significantly faster decay of correlation in the initial diffusive regime, which is in agreement with recent vibrational echo experiments.
Collapse
Affiliation(s)
- Deepak Ojha
- Dynamics of Condensed Matter and Center for Sustainable Systems Design, Department of Chemistry, University of Paderborn, Warburger Str. 100, D-33098 Paderborn, Germany
| | - Andrés Henao
- Dynamics of Condensed Matter and Center for Sustainable Systems Design, Department of Chemistry, University of Paderborn, Warburger Str. 100, D-33098 Paderborn, Germany
| | - Thomas D Kühne
- Dynamics of Condensed Matter and Center for Sustainable Systems Design, Department of Chemistry, University of Paderborn, Warburger Str. 100, D-33098 Paderborn, Germany
| |
Collapse
|
43
|
Liu J, He X, Zhang JZH, Qi LW. Hydrogen-bond structure dynamics in bulk water: insights from ab initio simulations with coupled cluster theory. Chem Sci 2018; 9:2065-2073. [PMID: 29675248 PMCID: PMC5885775 DOI: 10.1039/c7sc04205a] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 12/04/2017] [Indexed: 02/04/2023] Open
Abstract
An accurate and efficient ab initio molecular dynamics (AIMD) simulation of liquid water was made possible using the fragment-based approach (J. F. Liu, X. He and J. Z. H. Zhang, Phys. Chem. Chem. Phys., 2017, 19, 11931-11936). In this study, we advance the AIMD simulations using the fragment-based coupled cluster (CC) theory, more accurately revealing the structural and dynamical properties of liquid water under ambient conditions. The results show that the double-donor hydrogen-bond configurations in liquid water are nearly in balance with the single-donor configurations, with a slight bias towards the former. Our observation is in contrast to the traditional tetrahedral water structure. The hydrogen-bond switching dynamics in liquid water are very fast, with a hydrogen-bond life time of around 0.78 picoseconds, determined using AIMD simulation at the CCD/aug-cc-pVDZ level. This time scale is remarkably shorter than the ∼3.0 picoseconds that is commonly obtained from traditional nonpolarized force fields and density functional theory (DFT) based first-principles simulations. Additionally, the obtained radial distribution functions, triplet oxygen angular distribution, diffusion coefficient, and the dipole moment of the water molecule are uniformly in good agreement with the experimental observations. The current high-level AIMD simulation sheds light on the understanding of the structural and dynamical properties of liquid water.
Collapse
Affiliation(s)
- Jinfeng Liu
- State Key Laboratory of Natural Medicines , Department of Basic Medicine and Clinical Pharmacy , China Pharmaceutical University , Nanjing , 210009 , China .
| | - Xiao He
- School of Chemistry and Molecular Engineering , East China Normal University , Shanghai , 200062 , China
- NYU-ECNU Center for Computational Chemistry , NYU Shanghai , Shanghai , 200062 , China
| | - John Z H Zhang
- School of Chemistry and Molecular Engineering , East China Normal University , Shanghai , 200062 , China
- NYU-ECNU Center for Computational Chemistry , NYU Shanghai , Shanghai , 200062 , China
- Department of Chemistry , New York University , New York , NY 10003 , USA
| | - Lian-Wen Qi
- State Key Laboratory of Natural Medicines , Department of Basic Medicine and Clinical Pharmacy , China Pharmaceutical University , Nanjing , 210009 , China .
| |
Collapse
|
44
|
Stirnemann G, Duboué-Dijon E, Laage D. Ab Initio Simulations of Water Dynamics in Aqueous TMAO Solutions: Temperature and Concentration Effects. J Phys Chem B 2017; 121:11189-11197. [PMID: 29200289 DOI: 10.1021/acs.jpcb.7b09989] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We use ab initio molecular dynamics simulation to study the effect of hydrophobic groups on the dynamics of water molecules in aqueous solutions of trimethylamine N-oxide (TMAO). We show that hydrophobic groups induce a moderate (<2-fold) slowdown of water reorientation and hydrogen-bond dynamics in dilute solutions, but that this slowdown rapidly increases with solute concentration. In addition, the slowdown factor is found to vary very little with temperature, thus suggesting an entropic origin. All of these results are in quantitative agreement with prior classical molecular dynamics simulations and with the previously suggested excluded-volume model. The hydrophilic TMAO headgroup is found to affect water dynamics more strongly than the hydrophobic moiety, and the magnitude of this slowdown is very sensitive to the strength of the water-solute hydrogen-bond.
Collapse
Affiliation(s)
- Guillaume Stirnemann
- CNRS Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique, Univ. Paris Diderot, Sorbonne Paris Cité, PSL Research University , 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Elise Duboué-Dijon
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL Research University, Sorbonne Universités, UPMC Univ. Paris 06, CNRS , 75005 Paris, France
| | - Damien Laage
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL Research University, Sorbonne Universités, UPMC Univ. Paris 06, CNRS , 75005 Paris, France
| |
Collapse
|