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Related papers: Molecular dynamics simulations of $^1$H NMR relaxa…

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Molecular dynamics (MD) simulations are used to investigate $^1$H nuclear magnetic resonance (NMR) relaxation and diffusion of bulk $n$-C$_5$H$_{12}$ to $n$-C$_{17}$H$_{36}$ hydrocarbons and bulk water. The MD simulations of the $^1$H NMR…

Chemical Physics · Physics 2017-03-08 P. M. Singer , D. Asthagiri , W. G. Chapman , G. J. Hirasaki

In this contribution, we compute the $^1$H nuclear magnetic resonance (NMR) relaxation rate of liquid water at ambient conditions. We are using structural and dynamical information from Coupled Cluster Molecular Dynamics (CCMD) trajectories…

The translational-diffusion coefficient $D_T$ and the spin-rotation contribution to the $^1$H NMR relaxation time $T_{1J}$ for methane (CH$_4$) are investigated using MD (molecular dynamics) simulations, over a wide range of densities…

Chemical Physics · Physics 2018-06-13 Philip M. Singer , D. Asthagiri , Walter G. Chapman , George J. Hirasaki

The role of internal motions and molecular geometry on $^1$H NMR relaxation times $T_{1,2}$ in hydrocarbons is investigated using MD (molecular dynamics) simulations of the autocorrelation functions for in{\it tra}molecular $G_R(t)$ and…

It is the purpose of this paper to present a computational framework for reliably determining the frequency-dependent intermolecular and intramolecular NMR dipole-dipole relaxation rate of spin $1/2$ nuclei from MD simulations. The approach…

Soft Condensed Matter · Physics 2024-02-20 Dietmar Paschek , Johanna Busch , Eduard Mock , Ralf Ludwig , Anne Strate

The mechanism behind the NMR surface relaxation and the large $T_1$/$T_2$ ratio of light hydrocarbons confined in the nano-pores of kerogen remains poorly understood, and consequently has engendered much debate. Towards bringing a…

A model linking the molecular-scale dynamics of fluids confined to nano-pores to nuclear magnetic resonance (NMR) relaxation rates is proposed. The model is fit to experimental NMR dispersions for water and oil in an oil shale assuming that…

Mesoscale and Nanoscale Physics · Physics 2017-04-05 David A Faux , Peter J McDonald

An angular time-dependent probability density function describing Brownian or anomalous rotational dynamics of fixed-length atom-to-atom vectors is presented. The probability density function, which fully incorporates angular boundary…

Other Condensed Matter · Physics 2023-03-07 David A. Faux , Örs Istók , Arifah A. Rahaman , Peter J. McDonald , Eoin McKiernan , Dermot F. Brougham

The mechanism behind the $^1$H NMR frequency dependence of $T_1$ and the viscosity dependence of $T_2$ for polydisperse polymers and bitumen remains elusive. We elucidate the matter through NMR relaxation measurements of polydisperse…

1H spin-lattice relaxation experiments have been performed for water - Bovine Serum Al-bumin (BSA) mixtures including 20% wt and 40% wt of BSA. The experiments have been carried out in a frequency range encompassing three orders of…

Recent experiments on liquid water show collective dipole orientation fluctuations dramatically slower then expected (with relaxation time $>$ 50 ns) [D. P. Shelton, Phys. Rev. B {\bf 72}, 020201(R) (2005)]. Molecular dynamics simulations…

Soft Condensed Matter · Physics 2009-11-11 Pradeep Kumar , Giancarlo Franzese , Sergey V. Buldyrev , H. Eugene Stanley

The structure and dynamics of fluids confined in nanoporous media differ from those in bulk, which can be probed using NMR relaxation measurements. We here show, using atomistic molecular dynamics simulations of water in a slit nanopore,…

Soft Condensed Matter · Physics 2025-01-30 Simon Gravelle , Benoit Coasne , Christian Holm , Alexander Schlaich

Nuclear magnetic resonance relaxometry represents a powerful tool for extracting dynamic information. Yet, obtaining links to molecular motion is challenging for many ions that relax through the quadrupolar mechanism, which is mediated by…

Traditional theories of the NMR autocorrelation function for intramolecular dipole pairs assume single-exponential decay, yet the calculated autocorrelation of realistic systems display a rich, multi-exponential behavior resulting in…

The molecular dynamics (MD) simulation study of solvation structure and free energetics in 1-ethyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazolium hexafluorophosphate using a probe solute in the preceding article [Y. Shim, M.…

Soft Condensed Matter · Physics 2009-11-11 Y. Shim , M. Y. Choi , H. J. Kim

The intra-molecular $^1$H-NMR dipole-dipole relaxation of molecular fluids has traditionally been interpreted within the Bloembergen-Purcell-Pound (BPP) theory of NMR intra-molecular relaxation. The BPP theory draws upon Debye's theory for…

Chemical Physics · Physics 2020-09-15 D. Asthagiri , Walter G. Chapman , George J. Hirasaki , Philip M. Singer

While nuclear magnetic resonance (NMR) provides valuable insights into the local environment of many nuclei, the unambiguous interpretation of the signal in terms of microscopic dynamics is often difficult, particularly when the quadrupolar…

Chemical Physics · Physics 2025-02-11 Matthieu Wolf , Iurii Chubak , Benjamin Rotenberg

The fundamental understanding of intermolecular interactions of ionic liquids with water represents a vital extent in predicting ionic liquid properties. Intermolecular or noncovalent interactions were studied for 1,3-dimethyl imidazolium…

Chemical Physics · Physics 2022-06-14 Oleg N. Starovoytov

We demonstrate the application of implanted-ion $\beta$-detected NMR as a probe of ionic liquid molecular dynamics through the measurement of $^8$Li spin-lattice relaxation (SLR) and resonance in 1-ethyl-3-methylimidazolium acetate. The…

Understanding the dynamics of molecules adsorbed to surfaces or confined to small volumes is a matter of increasing scientific and technological importance. Here, we demonstrate a pulse protocol using individual paramagnetic nitrogen…

Mesoscale and Nanoscale Physics · Physics 2015-10-28 T. Staudacher , N. Raatz , S. Pezzagna , J. Meijer , F. Reinhard , C. A. Meriles , J. Wrachtrup
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