Incorrect K-point correspondance

Concerns any physical issues arising during the setup step (-i option). This includes problems with symmetries, k/q-point sets, and so on. For technical problems (running in parallel, etc), refer to the Technical forum.

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Incorrect K-point correspondance

Post by amolina » Fri Jul 18, 2014 4:14 pm

Dear all,

I have found a problem when I read the el-ph files with ypp_ph.

It seems that ypp_ph has problems to read the s.dph# files if I use certain precission in the k-points, when I generate them with pw.x.

For instance, if I use 5 decimal places without a zero at the end, ypp_ph will crash showing this message:
K = 0.44444 0.22222 0.0
PW(ELPH) databases ...[PHONON] ...incorrect K-point correspondance.

However, if use 4 decimal places with a zero at the end, like that
K = 0.44440 0.22220 0.0
ypp_ph is happy and reads the s.dph# files without problems.

Just in case somebody has this problem, take care of this...


Alejandro Molina-Sánchez
Institute of Materials Science (ICMUV)
University of Valencia, Spain

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Re: Incorrect K-point correspondance

Post by faozan » Mon Sep 18, 2017 1:03 am

Dear Dr. Alejandro and Yambo Developers,

I have a problem in calculating electron-phonon coupling on system with polarized spin/LSDA (nspin = 2). DFT and ph.x calculation on the system are finished well, I faced difficulties in running ypp_ph, there is always an error message "PW(ELPH) databases ...[PHONON] ...incorrect K-point correspondance" like in your case, I have followed your suggestion to change decimal precision on Kpoint, but the same problem still arose.
However, if use non-polarized approah (nspin = 1), everything running well; unfortunately I got the wrong electronic structure.
Could you please to give me any suggestion how to perform electron-phonon calculation on the top of LSDA?
thank you

Best regards,
Faozan Ahmad
PhD Student, ITB, Indonesia

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Davide Sangalli
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Re: Incorrect K-point correspondance

Post by Davide Sangalli » Sat Nov 11, 2017 5:36 pm

Ciao Alejandro,
can you open an issue on github related to this ?

Davide Sangalli, PhD
CNR-ISM, Division of Ultrafast Processes in Materials (FLASHit) and MaX Centre

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