I calculate phonon bandstructure which have alot of imaginary frequency. However I increase the supercell many times but does not work. ?

More Zeshan Zada's questions See All

In the context of publications, what mean by a quality research (publication) in mathematics?

Few options may be: 1. Number of citations of a paper 2. High Impact factor of a journal 3. Less number of authors ....

18 September 2019 1,048 31 View

Bayesian Generalized method of moment?

Any one who have the coding for the estimation of Bayesian generalized method of moment or any other help would be greatly appreciated.

12 November 2017 8,044 3 View

How to get the vector of a specific vibration mode in phonon dispersion?

For example, I have this phonon dispersion(Fig. 1), and now I would like get vector of atoms which describes TA1 in P. I know v_sim can show vibrational animation of specific mode, but I do not...

20 February 2021 4,332 4 View

Physical significance of Gap between optical and acosutic branches in Phonon Dispersion?

Hello Everyone, Recently I am doing some Phonon branchesbased studies. For some materials the gap between the optical and acoustic branch is small, for some it's large and for some there is no...

04 November 2020 3,987 2 View

How to calculate or experimentally determine phonon energy of oxide glasses?

I need to calculate phonon energy of different tellurite glass matrices. There are some ways through FTIR and Raman analysis that I know but they do not seem solid to apply and publish.

08 June 2020 1,607 5 View

Have Quantum Cascade Lasers been used to excite phonons (e.g. in solid-state samples)?

I am aware of many femtosecond laser based approaches to excite phonon modes e.g. in crystals and minerals. Quantum Cascade Lasers (QCLs) seem like an interesting alternative, especially since...

27 May 2020 5,464 3 View

Is it possible that the atoms can only have transverse mode of vibration in a crystal?

There are two possible modes of vibrations of atoms in the crystal, longitudinal and transverse. When we examine phonon dispersion curve or its band structure, usually both the modes can be...

12 April 2020 7,071 6 View

Anyone know about works, or currently working in modifying the nanostructure of Conventional Thermoelectric materials using Carbon nanostructures ?

Hello All: Does anyone is currently working, or know works about introducing carbon nanostructures in the material structure of the conventional thermoelectrics (like: Bi2Te3, Sb2Te3, Bi,SbTe,...

15 January 2020 4,336 3 View

How does one calculate the Huang-Rhys factor (S) with respect to the phonon displacement (Delta)?

Hello, I am trying to extract the Huang-Rhys factor S from the progression of LO phonon overtones in the resonance Raman spectrum of a material. In the configuration coordinate model, we consider...

08 January 2020 9,786 8 View

Which book is best for group theory in Raman spectroscopy?

I want to study about lattice dynamics of phonon mode ,phase transition using raman spectroscopy.can any body suggest me some book name for basic theory?

31 December 2019 4,520 4 View

Anyone know about works, or currently working in modifying the nanostructure of Conventional Thermoelectric materials using Carbon nanostructures ?

Hello All: Does anyone is currently working, or know works about introducing carbon nanostructures in the material structure of the conventional thermoelectrics (like: Bi2Te3, Sb2Te3, Bi,SbTe,...

31 December 2019 3,083 3 View

Is there a possibility of coupling between optical phonon and lone pair of electrons (lone pair electron-phonon coupling)?

The electron-phonon coupling is very common in condensed matter physics. But I am not sure if the same phenomenon is allowed between lone pair of electrons and phonon?.

26 November 2019 189 4 View