[Wien] Suggestions on PHONON Calculation 4

[Ghosh SUDDHASATTWA]

Dear Dr.Blaha, 

I am sorry I have posted this question before. 

I guess my querie may be inappropriate in the Wien2k mailing list. Still,
first I would request Prof. Blaha to kindly give me permission and help me
in sorting the issue in PHONON which actually is not a Wien2k problem. 

After I imported the case.dsy file ( forces convergence obtained with 0.005
mRy) in phonon software and incorporated the lattice parameters of the
supercell and the number of atoms, I applied the translational and
rotational  invariances, I get the Do Report in PHONON. 

I get the plot of force constants and I subsequently get the phonon
dispersion. I get some imaginary frequencies which I am not sure if it is
because of the wrong choice of supercell size (12 atoms) or the force
convergence (0.005 mRy/atom) 

Can you please help me in this regard? 

Can I send you the case.dsy for your perusal? 

 

Thank you 

Suddhasattwa 

 

 

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