I have another question. I have investigated phonon dispersion & there is a negative value -.0005. Does it still consider as dynamically unstable??

More Mohshina Mansur's questions See All

My transduced cell can resist Puromycin and 99% express GFP, BUT can not show me the difference in the knockdown. what could be the possible reason?

My transduced cell can resist Puromycin and 99% express GFP, but it cannot show me the difference in the knockdown. What could be the possible reason?

31 May 2024 454 2 View

What are the possible reason(s) that make AsPC-1, 293T and MCF-7 cell lines failed to be transfect/transduced?. Please help me with possible hints?

what are the possible reason(s) that make AsPC-1, 293T and MCF-7 cell lines failed to be transfect/transduced?. Please help me with possible hints?

10 March 2024 8,812 2 View

Is it possible perovskite with Flourine will have lower band gap compared to Cl ?

I have calculated band structure of a halide perovskite consisting Flourine but its gap is lower than the perovskite with Cl how is this possible?

28 February 2024 1,527 1 View

If the melting temparature of a half heusler is below 1200 degree celcius, can we use it application? i saw various compounds having temp above 1500 ?

nothing

08 November 2023 5,318 0 View

How can i dissolve PALMITIC ACID?

Please i have been trying to dissolve Palmitic acid in BSA-NaOH, it keeps solidifying after heating. I wanted to used DMSO but its' lethal to cells. And also the DMSO recommended concentration to...

25 September 2023 990 1 View

If i want to calculate heat capacity for half Heusler compound is the heat capacity equation will be same i used in halaideperovskite compound in DFT?

18 September 2023 6,998 0 View

Is it possible for a semiconductore to increase band gap while applying pressure then after certain pressure ,then band gap will decrease again?

Half heusler alloy electronic property under pressure

12 August 2023 5,002 3 View

Can I perform a Benjamini Hochberg FDR correction over p values from different tests?

I'm performing statistical analysis on a time series data, comparing the average amplitude (y axis) between three groups on every 50 ms (x axis). The time series is 1200 ms long (so in total 24...

21 October 2020 3,568 3 View

Apart from Questionnaires and Checklists, what are the other instruments used for collecting data in a survey research?

Questionnaires and Checklists seem to be the most widely instruments used for data collection in survey studies among undergraduate Students.

12 June 2019 4,793 5 View

Can I study the combined effect of two independent variables on one dependent variables?

RQ1. To what extent, if any, is there a relationship between project manager’s cultural intelligence and IT project success? RQ2. To what extent, if any, is there a relationship between project...

29 May 2018 8,016 20 View

I am trying to find phonon, and when i run calculations, there is error ?

how to fix this error, from phq_readin : error # 1 DFPT with the Blochl correction is not implemented I am attaching my ph.in file.

23 July 2024 4,649 2 View

How to eliminate imaginary phonon frequency in phonon dispersion of Coved Graphene Nanoribbons?

Dear all, I want to calculate the phonon dispersion of 4CNR-1-0 (structure is in Fig. 2 (b) in this article Designing coved graphene nanoribbons with charge carrier mob... ) and then calculate...

17 June 2024 6,911 2 View

Can the debye temperature calculated using elastic sound velocity be used in Slack model to find Thermal conductivity?

I am trying to calculate lattice thermal conductivity using Slack model. In Slack model the lattice thermal conductivity is proportional to (Debye temperature)^3. Can I use the Debye temperature...

11 June 2024 1,719 1 View

How to parallelize "Phonon Dispersion" Calculation in QE v7.2?

I am trying to perform ph.x calculations on lead-halide perovskite primitive cell with `8 8 8` k points in scf calculation and `6 6 6` q -point grid. The calculation is computationally expensive...

12 May 2024 6,276 0 View

Difficulty in reproducing Phonon Surface State calculation using Wannier Tools package ?

I am attempting to reproduce phonon surface state calculations using the Wannier tools package. In the first step, I aim to obtain the phonon tight binding Hamiltonian from force constants or...

01 May 2024 3,029 2 View

What causes bandgaps in periodic media?

I am aware that periodically layered media (if structured properly) can produce bandgaps, however I have never found a great explanation for this in the phononics case. Can someone please provide...

30 April 2024 9,681 4 View

Do the bottom layers of the slab need to be fixed when we use DFPT or finite displacement methods to compute the phonon spectrum of a surface?

When using DFPT or the finite displacement (also known as the frozen phonon) method to compute surface phonon spectra, it is generally necessary to perform high-precision optimization on the slab...

22 April 2024 8,385 0 View

How to read the atomic displacement in Phonon Calculation in QE?

I have a long-standing question that I hope you can help me with. In phonon calculations within QE, we obtain vibration frequencies and eigenvectors from the matdyn.out file. I am particularly...

07 April 2024 299 3 View

Can we use Density Functional Theory (DFT) to calculate the second and third-order force constants of a slab?

If we aim to compute the surface phonon lifetime of a Cu(111) surface, the second and third-order force constants are essential (to put in Boltzmann transport equation). However, to my knowledge,...

07 April 2024 6,677 4 View

We found a Raman peak in the silver powder around 1000 cm-1. What could be the origin of this peak?

As we know, for Raman spectroscopy, a change in dielectric constant is required w.r.t. phonons, which does not apply to metals. Therefore, pure metals are Raman inactive. Also, this 1000 cm-1 peak...

02 March 2024 1,856 4 View

Şükrü Aktaş

Fonon değerinin negatif olması onun kararsız olduğunu ispatlamaz. Fononun kararlı veya kararsız olduğunu anlamak için sahip olduğu kinetik enerjiye bakılabilir.

Andreas Goebel

Just run that calculation with slightly different settings and figure out what your numerical noise is first; also:

What units does that value have? eV, meV, cm^-1?

Md. Harun-Or-Rashid

You can further run it by changing its cut off frequency (increasing than the previous one). Now it is dynamically unstable.