Why Phonon dispersion curve is not smooth???

[vishchandan007]

I am trying to calculate the Phonon dispersion curve for NaBaSb. Here, I am attaching the calculated plot up to the Harmonic level, i.e., NORDER = 1. I am not able to rectify why the plot is not smooth. Please let me know if anyone can help me out.

Regards
Chandan

[ttadano]

Please check if you are correctly using a primitive lattice vectors for the &cell in ANPHON.

[vishchandan007]

Dear Tadano,

Thank you for your reply. I checked my input files, and based on my knowledge, I think the input files are correct.
However, I am attaching the input files for NaBaSb, including the POSCAR, input of anphon, and output for your reference. Please let me know if I am making any silly mistakes in the calculation.

Thanks and regards,
Chandan
IIT Delhi, India

NBT_input.zip

[ttadano]

Hi,

I've checked your input and found you used the supercell lattice parameters for the &cell field in nbs_phband.in. Please use the primitive cell lattice parameters instead.

[vishchandan007]

Dear Tadano,

Thank you for your reply. After incorporating your suggestion, I am getting a perfect phonon dispersion curve.

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Chandan