Reststrahlen of Alkali Halides in the Far-Infrared Region

1973 ◽  
Vol 51 (17) ◽  
pp. 1898-1899
Author(s):  
A. F. Leung
Keyword(s):  
Optical Properties ◽  
Harmonic Oscillator ◽  
Alkali Halides ◽  
Far Infrared ◽  
Infrared Region ◽  
Oscillator Model ◽  
Simple Harmonic Oscillator ◽  
Harmonic Oscillator Model

The assumption in deriving the Lyddane–Sachs–Teller relation and the simple harmonic oscillator model do not hold well in the understanding of the optical properties of alkali halides in the far-infrared region.

scholarly journals Simple Harmonic Oscillator Model of O2 Molecule in Vacuum: A Classical Molecular Dynamics Study

2018 ◽  
Vol 4 (1) ◽  
pp. 8-16
Author(s):  
Salmahaminati Salmahaminati
Keyword(s):  
Molecular Dynamics ◽  
Harmonic Oscillator ◽  
Electronic Transitions ◽  
Oscillator Model ◽  
Quantum Mechanical ◽  
Vibrational Modes ◽  
Simple Harmonic Oscillator ◽  
Quantum Mechanical Description ◽  
Harmonic Oscillator Model ◽  
Basic Understanding

The simple harmonic oscillator model allows a basic understanding of all processes and can be used to analyse optical vibrational modes and electronic transitions in atoms, molecules and crystals, in order to derive general properties of harmonic generation to all orders. In particular, we are done to investigate single, ten, and twenty harmonic oscillator of O2 molecule using GROMACS 4.55. Time is the important factor in simulation because the best result of simulation can be obtained by increasing the number of steps and by decreasing the timesteps. Since the properties only depend on time and not on the specific microscopic model, they can also be adopted for the quantum-mechanical description by using in the classical molecular dynamics. 

scholarly journals Absorption Ångström coefficient, brown carbon, and aerosols: basic concepts, bulk matter, and spherical particles

2010 ◽  
Vol 10 (10) ◽  
pp. 24735-24761 ◽  
Author(s):  
H. Moosmüller ◽  
R. K. Chakrabarty ◽  
K. M. Ehlers ◽  
W. P. Arnott
Keyword(s):  
Harmonic Oscillator ◽  
Band Gap ◽  
Absorption Spectra ◽  
Spherical Particles ◽  
Oscillator Model ◽  
Gap Model ◽  
Brown Carbon ◽  
Urbach Tail ◽  
Simple Harmonic Oscillator ◽  
Harmonic Oscillator Model

Abstract. The concept of wavelength dependent absorption Ångström coefficients (AACs) is discussed and clarified for both single and two-wavelengths AACs and guidance for their implementation with noisy absorption spectra is provided. This discussion is followed by application of the concept to models for brown carbon bulk absorption spectra including the damped simple harmonic oscillator model, its Lorentzian approximation, and the band-gap model with and without Urbach tail. We show that the band-gap model with Urbach tail always has an unphysical discontinuity in the first derivative of the AAC at the band-gap – Urbach-tail matching wavelength. Complex refractive indices obtained from the bulk damped simple harmonic oscillator model are used to calculate absorption spectra for spherical particles, followed by a discussion of their features. For bulk material and small particles, this model predicts a monotonic decrease of the AAC with wavelength well above the resonance wavelength; the model predicts a monotonic increase for large particles.

Phenomenology of inflationary models

2018 ◽  
Vol 33 (03) ◽  
pp. 1850018
Author(s):  
Abbas olyaei
Keyword(s):  
Harmonic Oscillator ◽  
Observational Data ◽  
Oscillator Model ◽  
Simple Harmonic Oscillator ◽  
Harmonic Oscillator Model ◽  
Single Field ◽  
Inflationary Models ◽  
Good Agreement

There are many inflationary models compatible with observational data. One can investigate inflationary models by looking at their general features, which are common in most of the models. Here we have investigated some of the single-field models without considering their origin in order to find the phenomenology of them. We have shown how to adjust the simple harmonic oscillator model in order to be in good agreement with observational data.

scholarly journals Absorption Ångström coefficient, brown carbon, and aerosols: basic concepts, bulk matter, and spherical particles

2011 ◽  
Vol 11 (3) ◽  
pp. 1217-1225 ◽  
Author(s):  
H. Moosmüller ◽  
R. K. Chakrabarty ◽  
K. M. Ehlers ◽  
W. P. Arnott
Keyword(s):  
Harmonic Oscillator ◽  
Band Gap ◽  
Absorption Spectra ◽  
Spherical Particles ◽  
Oscillator Model ◽  
Gap Model ◽  
Brown Carbon ◽  
Urbach Tail ◽  
Simple Harmonic Oscillator ◽  
Harmonic Oscillator Model

Abstract. The concept of wavelength-dependent absorption Ångström coefficients (AACs) is discussed and clarified for both single and two-wavelengths AACs and guidance for their implementation with noisy absorption spectra is provided. This discussion is followed by application of the concept to models for brown carbon bulk absorption spectra including the damped simple harmonic oscillator model, its Lorentzian approximation, and the band-gap model with and without Urbach tail. We show that the band-gap model with Urbach tail always has an unphysical discontinuity in the first derivative of the AAC at the band-gap – Urbach-tail matching wavelength. Complex refractive indices obtained from the bulk damped simple harmonic oscillator model are used to calculate absorption spectra for spherical particles, followed by a discussion of their features. For bulk material and small particles, this model predicts a monotonic decrease of the AAC with wavelength well above the resonance wavelength; the model predicts a monotonic increase for large particles.

scholarly journals Broadband spectroscopy of astrophysical ice analogues

2019 ◽  
Vol 629 ◽  
pp. A112 ◽  
Author(s):  
B. M. Giuliano ◽  
A. A. Gavdush ◽  
B. Müller ◽  
K. I. Zaytsev ◽  
T. Grassi ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Time Domain ◽  
Complex Refractive Index ◽  
Far Infrared ◽  
Infrared Region ◽  
Thz Radiation ◽  
The Real ◽  
Thz Range ◽  
The Time Domain

Context. Reliable, directly measured optical properties of astrophysical ice analogues in the infrared and terahertz (THz) range are missing from the literature. These parameters are of great importance to model the dust continuum radiative transfer in dense and cold regions, where thick ice mantles are present, and are necessary for the interpretation of future observations planned in the far-infrared region. Aims. Coherent THz radiation allows for direct measurement of the complex dielectric function (refractive index) of astrophysically relevant ice species in the THz range. Methods. We recorded the time-domain waveforms and the frequency-domain spectra of reference samples of CO ice, deposited at a temperature of 28.5 K and annealed to 33 K at different thicknesses. We developed a new algorithm to reconstruct the real and imaginary parts of the refractive index from the time-domain THz data. Results. The complex refractive index in the wavelength range 1 mm–150 μm (0.3–2.0 THz) was determined for the studied ice samples, and this index was compared with available data found in the literature. Conclusions. The developed algorithm of reconstructing the real and imaginary parts of the refractive index from the time-domain THz data enables us, for the first time, to determine the optical properties of astrophysical ice analogues without using the Kramers–Kronig relations. The obtained data provide a benchmark to interpret the observational data from current ground-based facilities as well as future space telescope missions, and we used these data to estimate the opacities of the dust grains in presence of CO ice mantles.

The harmonic oscillator model in predissociation

1978 ◽  
Vol 33 (2) ◽  
pp. 205-217 ◽  
Author(s):  
Michael L. Sink ◽  
André D. Bandrauk
Keyword(s):  
Harmonic Oscillator ◽  
Oscillator Model ◽  
Harmonic Oscillator Model
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