Dynamical Structure Factor and Vibrational Normal Modes of SiO2 Glass

1992 ◽  
Vol 291 ◽  
Author(s):  
Wei Jin ◽  
Rajiv K. Kalia ◽  
Priya Vashishta
Keyword(s):  
Molecular Dynamics ◽  
Structure Factor ◽  
Interatomic Potential ◽  
Inelastic Neutron Scattering ◽  
Normal Modes ◽  
Dynamic Structure ◽  
Md Simulations ◽  
Inelastic Neutron ◽  
Dynamical Structure ◽  
Dynamical Matrix

ABSTRACTWe study the atomic vibrational dynamics in silica glass (a-SiO2) using molecular-dynamics (MD) simulations and classical lattice dynamics method. The SiO2 glasses were generated by molecular-dynamics and steepest-descent quench (SDQ) using an effective interatomic potential consisting of two-body and three-body interactions. The frequency and eigenvectors of vibrational normal modes are obtained by diagonalization of the dynamical matrix. The partial and total vibrational density of states (DOS), bond-projected DOS, participation ratio (PR), and neutron-weighted dynamic structure factor are calculated. The results are compared with inelastic neutron scattering experiments on SiO2 glass.

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.

Dynamical Structure Factor of Magnetic Excitation in Underdoped La1.90Sr0.10CuO4 Measured by Chopper Neutron Spectrometer

2014 ◽  
Vol 616 ◽  
pp. 291-296
Author(s):  
Kentaro Sato ◽  
Masato Matsuura ◽  
Masanori Enoki ◽  
Kazuyoshi Yamada ◽  
Masaki Fujita
Keyword(s):  
Neutron Scattering ◽  
Structure Factor ◽  
Inelastic Neutron Scattering ◽  
Parent Compound ◽  
Inelastic Neutron ◽  
Hole Doping ◽  
Dynamical Structure ◽  
Dynamical Structure Factor ◽  
Neutron Spectrometer ◽  
Scattering Intensity

We have performed inelastic neutron scattering measurement on high-transition temperature superconductor La1.90Sr0.10CuO4 with utilizing a Fermi chopper spectrometer. We succeeded in converting the observed neutron scattering intensity into a dynamical structure factor in the absolute unit by attempting two methods with analyzing (i) incoherent scattering intensity from the sample itself and (ii) that from vanadium standard. The total squared moment <M2> was evaluated to be 0.176 μB2/Cu, which is much smaller than the value for the parent compound, indicating a markedly change of electronic state by hole-doping.

Dynamic structure factor in a nonequilibrium fluid: A molecular-dynamics approach

1992 ◽  
Vol 45 (10) ◽  
pp. 7180-7183 ◽  
Author(s):  
M. Mareschal ◽  
M. Malek Mansour ◽  
G. Sonnino ◽  
E. Kestemont
Keyword(s):  
Molecular Dynamics ◽  
Structure Factor ◽  
Dynamic Structure ◽  
Dynamic Structure Factor

Molecular dynamics in gaseous and solid methane studied by the inelastic neutron scattering method

Physica ◽  
1969 ◽  
Vol 41 (3) ◽  
pp. 397-408 ◽  
Author(s):  
A. Bajorek ◽  
I. Natkaniec ◽  
K. Parliński ◽  
M. Sudnik-Hrynkiewicz ◽  
J.A. Janik ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Neutron Scattering ◽  
Inelastic Neutron Scattering ◽  
Inelastic Neutron ◽  
Scattering Method ◽  
Solid Methane

Analysis of Heat Conduction in Silicon Using Molecular Dynamics Simulations

2006 ◽  
Author(s):  
Asegun S. Henry ◽  
Gang Chen
Keyword(s):  
Molecular Dynamics ◽  
Lattice Dynamics ◽  
Crystalline Silicon ◽  
Relaxation Times ◽  
Normal Modes ◽  
Md Simulations ◽  
Dynamics Simulations ◽  
Technological Significance ◽  
Fitting Parameters ◽  
Phonon Properties

Silicon's material properties, have been studied extensively because of its technological significance in a variety of industries, including microelectronics. Yet, questions surrounding the phonon relaxation times in silicon continue to linger.1,2 Previous theoretical works3-5 have generated qualitative expressions for phonon relaxation times, however these approaches require fitting parameters that cannot be determined reliably. This paper first discusses implementation issues associated with using the Green-Kubo method in molecular dynamics (MD) simulations. We compare various techniques used in similar works and discusses several implementation issues that have arisen in the literature. We then describe an alternative procedure for analyzing the normal modes of a crystal to extract phonon relaxation times. As an example material we study bulk crystalline silicon using equilibrium MD simulations and lattice dynamics. The environment dependent interatomic potential6 is used to model the interactions and frequency dependent phonon properties are extracted from the MD simulations.

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