Messages

1

General Questions and Answers / Raman spectra calculation

« on: August 29, 2021, 16:27 »

Is it possible to calculate Raman spectra for different temperatures?

2

General Questions and Answers / Re: Negative energy in phonon band structure calculation

« on: September 13, 2020, 08:48 »

Sir as per your suggestion I have performed phonon band structure calculation for 2*2*1 super cell. But the system still have negative energy of -6.18 meV which is earlier -6.27 for unit cell. To further increase the super cell size is very difficult for computation. Could you please suggest any other way to solve this?
I am attaching here input and output for your reference.

3

General Questions and Answers / Re: Negative energy in phonon band structure calculation

« on: September 3, 2020, 18:47 »

What  do you mean by bigger cell? whether you want to mean that I have to design a  super cell and re-optimize it and followed by phonon band structure calculation or you want to mean that I have to increase the size of the lattice vector of the unit cell and re-optimize it and followed by phonon band structure calculation. Kindly enlighten me on this topic.

4

General Questions and Answers / Negative energy in phonon band structure calculation

« on: September 1, 2020, 20:23 »

I am a beginner in quantum ATK and facing a problem during phonon band structure calculation I am getting negative energy states. Could you please suggest me how to overcome this?
I have re optimized the structure with high force and stress tolerance but unable to get the correct phonon band structure. I am attaching the inputs and outputs for your reference.