ABINIT Discussion Forums

Dear everyone,

I'm a new abinit user and I'm trying to calculate the phonon DOS for a NiTi compound, but I'm not getting the same result as reported in the literature.
I just modified the input files in the tutorials to match my system. The general shape of the PDOS looks ok, but the frequencies seem to be shifted up by ~1 THz, and that branch near gamma looks bad.

Can someone help me to understand what's wrong with my model?
I'm using the norm-conserving pseudopotentials available in the abinit webpage.

Abinit output:


Reported in literature:






Thanks

Dear disae,

1. First, this is not phonon DOS, but phonon dispersion curves.

2. The differences you see can be the result of many factors: approximation used in the calculation, unconverged calculation parameters, unrelaxed structure, and similar. There are many things you should check first, before trying to compare your results with some other. And you have to be specially careful if you are comparing to the experimental results. Frequency shifts of 1 THz are not unseen before. All in all, I would say that your results are good.

Best regards,

Igor