scholarly journals Studies of Hydrogen Bond Vibrations of Hydrogen-Disordered Ice Ic

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 668
Author(s):  
Xu-Hao Yu ◽  
Xiao-Ling Qin ◽  
Xiao-Tong Dong ◽  
Jing-Wen Cao ◽  
Xu-Liang Zhu ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Neutron Scattering ◽  
Density Functional ◽  
Inelastic Neutron Scattering ◽  
General Rule ◽  
Far Infrared ◽  
Infrared Region ◽  
Inelastic Neutron ◽  
Energy Splitting ◽  
Bond Peak

The hydrogen-disordered structure of ice, Ic, makes it difficult to analyze the vibrational normal modes in the far-infrared region (i.e., the molecular translation band). To clarify the origin of the energy-splitting of hydrogen bond vibrations in this area, a 64-molecule supercell was constructed and calculated using first-principles density functional theory. The results were in good agreement with inelastic neutron scattering experiments and our previous study of a hydrogen-ordered ice Ic model. Assisted by analytic equations, we concluded that the origin of the two hydrogen bond peaks in real ice Ic is consistent with that of hydrogen-ordered ice Ic: the peaks originate from two kinds of normal mode vibration. We categorize the four peaks in the far-infrared region recorded from inelastic neutron scattering experiments as the acoustic peak, the superposition peak, the two-hydrogen bond peak and the four-hydrogen bond peak. We conclude that the existence of two intrinsic hydrogen bond vibration modes represents a general rule among the ice family, except ice X.

scholarly journals Study of Anharmonicity in Zirconium Hydrides Using Inelastic Neutron Scattering and Ab-Initio Computer Modeling

Inorganics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 29
Author(s):  
Jiayong Zhang ◽  
Yongqiang Cheng ◽  
Alexander I. Kolesnikov ◽  
Jerry Bernholc ◽  
Wenchang Lu ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Excited States ◽  
Lattice Dynamics ◽  
Density Functional ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Vibrational States ◽  
Functional Theory ◽  
Hydrogen Deuterium ◽  
Zirconium Hydrides

The anharmonic phonon behavior in zirconium hydrides and deuterides, including ϵ-ZrH2, γ-ZrH, and γ-ZrD, has been investigated from aspects of inelastic neutron scattering (INS) and lattice dynamics calculations within the framework of density functional theory (DFT). The harmonic model failed to reproduce the spectral features observed in the experimental data, indicating the existence of anharmonicity in those materials and the necessity of further explanations. Here, we present a detailed study on the anharmonicity in zirconium hydrides/deuterides by exploring the 2D potential energy surface of hydrogen/deuterium atoms and solving the corresponding 2D single-particle Schrödinger equation to obtain the eigenfrequencies, which are then convoluted with the instrument resolution. The convoluted INS spectra qualitatively describe the anharmonic peaks in the experimental INS spectra and demonstrate that the anharmonicity originates from the deviations of hydrogen potentials from quadratic behavior in certain directions; the effects are apparent for the higher-order excited vibrational states, but small for the ground and first excited states.

scholarly journals DFT Simulations of the Vibrational Spectrum and Hydrogen Bonds of Ice XIV

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1781 ◽  
Author(s):  
Kai Zhang ◽  
Peng Zhang ◽  
Ze-Ren Wang ◽  
Xu-Liang Zhu ◽  
Ying-Bo Lu ◽  
...  
Keyword(s):  
Vibrational Spectrum ◽  
Normal Vibration ◽  
Density Functional ◽  
Inelastic Neutron Scattering ◽  
General Rule ◽  
Experimental Spectrum ◽  
Inelastic Neutron ◽  
Functional Theory ◽  
Ir And Raman ◽  
Normal Vibration Frequencies

It is always a difficult task to assign the peaks recorded from a vibrational spectrum. Herein, we explored a new pathway of density functional theory (DFT) simulation to present three kinds of spectra of ice XIV that can be referenced as inelastic neutron scattering (INS), infrared (IR), and Raman experimental spectrum. The INS spectrum is proportional to the phonon density of states (PDOS) while the photon scattering signals reflect the normal vibration frequencies near the Brillouin zone (BZ) center. Based on good agreements with the experimental data, we identified the relative frequency and made scientific assignments through normal vibration modes analysis. The two hydrogen bond (H-bond) peaks among the ice phases from INS were discussed and the dynamic process of the H-bond vibrations was found to be classified into two basic modes. We deduced that two H-bond modes are a general rule among the ice family and more studies are ongoing to investigate this subject.

Low-frequency single-crystal Raman, far-infrared, and inelastic neutron scattering studies of acetanilide at low temperature

1991 ◽  
Vol 95 (13) ◽  
pp. 5281-5286 ◽  
Author(s):  
Clifford T. Johnston ◽  
Stephen F. Agnew ◽  
Juergen Eckert ◽  
Llewellyn H. Jones ◽  
Basil I. Swanson ◽  
...  
Keyword(s):  
Low Temperature ◽  
Neutron Scattering ◽  
Single Crystal ◽  
Inelastic Neutron Scattering ◽  
Low Frequency ◽  
Far Infrared ◽  
Inelastic Neutron

An inelastic neutron scattering, Raman, far-infrared, and molecular dynamics study of the intermolecular dynamics of two ionic liquids

2020 ◽  
Vol 22 (16) ◽  
pp. 9074-9085 ◽  
Author(s):  
Thamires A. Lima ◽  
Vitor H. Paschoal ◽  
Rafael S. Freitas ◽  
Luiz F. O. Faria ◽  
Zhixia Li ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Ionic Liquids ◽  
Power Spectrum ◽  
Neutron Scattering ◽  
Inelastic Neutron Scattering ◽  
Far Infrared ◽  
Md Simulations ◽  
Inelastic Neutron ◽  
Tetraalkylammonium Cations

The THz dynamics of ionic liquids based on tetraalkylammonium cations were investigated by a combined usage of inelastic neutron scattering (INS), Raman, and far-infrared (FIR) spectroscopies and the power spectrum calculated by molecular dynamics (MD) simulations.

scholarly journals On the microscopic dynamics of the ‘Einstein solids’ AlV2Al20 and GaV2Al20, and of YV2Al20: a benchmark system for ‘rattling’ excitations

2015 ◽  
Vol 17 (38) ◽  
pp. 24837-24850 ◽  
Author(s):  
Michael Marek Koza ◽  
Hannu Mutka ◽  
Yoshihiko Okamoto ◽  
Jun-ichi Yamaura ◽  
Zenji Hiroi
Keyword(s):  
Density Functional Theory ◽  
High Resolution ◽  
Neutron Scattering ◽  
Lattice Dynamics ◽  
Density Functional ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Functional Theory ◽  
Inelastic Response ◽  
Benchmark System

The inelastic response of AV2Al20 (with A = Al, Ga and Y) was probed by high-resolution inelastic neutron scattering experiments and density functional theory (DFT) based lattice dynamics calculations (LDC).

scholarly journals Solid wetting-layers in inorganic nano-reactors: the water in imogolite nanotube case

2020 ◽  
Vol 2 (5) ◽  
pp. 1869-1877 ◽  
Author(s):  
Geoffrey Monet ◽  
Erwan Paineau ◽  
Ziwei Chai ◽  
Mohamed S. Amara ◽  
Andrea Orecchini ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Density Functional Theory ◽  
Neutron Scattering ◽  
Density Functional ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Original Structure ◽  
Functional Theory ◽  
Inner Surface ◽  
Wetting Layers

The discovery of an original structure of the water at the inner surface of inorganic aluminogermanate nanotubes and its specific dynamics are reported, based on density functional theory molecular dynamics and inelastic neutron scattering.

Sign in / Sign up

Export Citation Format

Share Document