Effect of Ti insertion in the silicalite framework on the vibrational modes of the structure: an ab initio, and vibrational study

2001 ◽  
pp. 195-208 ◽  
Author(s):  
A. Damin ◽  
G. Ricchiardi ◽  
S. Bordiga ◽  
A. Zecchina ◽  
F. Ricci ◽  
...  
Keyword(s):  
Ab Initio ◽  
Vibrational Modes ◽  
Vibrational Study

scholarly journals Phonons in Short-Period GaN/AlN Superlattices: Group-Theoretical Analysis, Ab initio Calculations, and Raman Spectra

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 286
Author(s):  
Valery Davydov ◽  
Evgenii Roginskii ◽  
Yuri Kitaev ◽  
Alexander Smirnov ◽  
Ilya Eliseyev ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Raman Spectra ◽  
Density Functional ◽  
Structural Characteristics ◽  
Vibrational Modes ◽  
Phonon Modes ◽  
Short Period ◽  
Group Theoretical Analysis

We report the results of experimental and theoretical studies of phonon modes in GaN/AlN superlattices (SLs) with a period of several atomic layers, grown by submonolayer digital plasma-assisted molecular-beam epitaxy, which have a great potential for use in quantum and stress engineering. Using detailed group-theoretical analysis, the genesis of the SL vibrational modes from the modes of bulk AlN and GaN crystals is established. Ab initio calculations in the framework of the density functional theory, aimed at studying the phonon states, are performed for SLs with both equal and unequal layer thicknesses. The frequencies of the vibrational modes are calculated, and atomic displacement patterns are obtained. Raman spectra are calculated and compared with the experimental ones. The results of the ab initio calculations are in good agreement with the experimental Raman spectra and the results of the group-theoretical analysis. As a result of comprehensive studies, the correlations between the parameters of acoustic and optical phonons and the structure of SLs are obtained. This opens up new possibilities for the analysis of the structural characteristics of short-period GaN/AlN SLs using Raman spectroscopy. The results obtained can be used to optimize the growth technologies aimed to form structurally perfect short-period GaN/AlN SLs.

High Energy Local Vibrational Modes of Carbon Aggregates in SiC: Experimental and Theoretical Insight

2006 ◽  
Vol 527-529 ◽  
pp. 465-468 ◽  
Author(s):  
Alexander Mattausch ◽  
M. Bockstedte ◽  
Oleg Pankratov ◽  
John W. Steeds ◽  
S.A. Furkert ◽  
...  
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
High Energy ◽  
Vibrational Modes ◽  
Energy Mode ◽  
Local Vibrational Modes ◽  
Theoretical Insight

We observe new photoluminescence centers in electron-irradiated 6H-SiC with phonon replicas up to 250 meV and clear threefold isotope splitting of the highest energy mode. Based on ab initio calculations, we discuss the tri-carbon anti-site (C3)Si and the di-interstitial (C2)Hex as models for these centers.

Solvation effects on the vibrational modes in hydrated bicarbonate clusters

2018 ◽  
Vol 20 (6) ◽  
pp. 4571-4578 ◽  
Author(s):  
Xiangtao Kong ◽  
Shou-Tian Sun ◽  
Ling Jiang ◽  
Zhi-Feng Liu
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Harmonic Analysis ◽  
Molecular Dynamics Simulations ◽  
Vibrational Modes ◽  
Solvation Effects ◽  
Dynamics Simulations

Harmonic analysis and ab initio molecular dynamics simulations reveal the solvation effects on the vibrational modes of HCO3−(H2O)n.

Vibrational modes in thymine molecule from an ab initio MO calculation

1997 ◽  
Vol 53 (3) ◽  
pp. 393-407 ◽  
Author(s):  
Misako Aida ◽  
Motohisa Kaneko ◽  
Michel Dupuis ◽  
Toyotoshi Ueda ◽  
Koichi Ushizawa ◽  
...  
Keyword(s):  
Ab Initio ◽  
Vibrational Modes ◽  
Mo Calculation ◽  
Ab Initio Mo

Experimental and ab initio study of vibrational modes of stressed alumina films formed by oxidation of aluminium alloys under different atmospheres

2011 ◽  
Vol 59 (7) ◽  
pp. 2723-2730 ◽  
Author(s):  
W.W. Peng ◽  
P. Roy ◽  
L. Favaro ◽  
E. Amzallag ◽  
J.B. Brubach ◽  
...  
Keyword(s):  
Ab Initio ◽  
Aluminium Alloys ◽  
Vibrational Modes ◽  
Ab Initio Study ◽  
Alumina Films
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