[Pw_forum] electron-phonon unity mode output

[Shela Aboud]

After running the electron-phonon calculation there are a series of modes that are printed in the output file. For some of the phonon vectors the pattern of the modes look like the expected displacements but for other modes is gives a series of zeros with a -1 cycled through the different (x,y,z) coordinates. For example for a simulation with a 2 atom basis one of the modes look like the following:

Representation 1 1 mode –A_1 D_1 S_1
…
mode #1
(0.00000    0.00000)
(0.00000    0.00000)
(-1.00000   0.00000)
(0.00000    0.00000)
(0.00000    0.00000)
(0.00000    0.00000)
(0.00000    0.00000)

the rest of the 6 modes are identical with the "-1" cycled through each of the real (x,y,z) components of atom 1 and atom 2. Does someone know what this means? I ran across a similar post on the forum but there was no reply. 

Thanks,
Shela