[Pw_forum] the meaning of gx, gy and gz in PDOS of phonon from QHA code

[GAO Zhe]

 Dear PWscf Developer and Users:
I am using QHA code to calculate thermodynamic properties for highly-ordered doping cubic system, such like:
ibrav = 1 ,
ATOMIC_POSITION crystal
  A  0.0  0.0  0.0
  B  0.0  0.5  0.5
  B  0.5  0.0  0.5
  B  0.5  0.5  0.0
  C  0.5  0.0  0.0
  C  0.0  0.5  0.0
  C  0.0  0.0  0.5
  C  0.5  0.5  0.5
When I checked the files named projected_DOS.Xi, except the PDOS of Xi atom itself, gx, gy and gz are also listed in the last three columns.
At beginning, I thought gx, gy and gz must represent the vibrations on x,y,z directions, respectively. However, I found the values of gx, gy and gz are significantly different with each other, especially for the atom with different kinds elements as nearest neighbor atoms.
Since my model is cubic and with high symmetry, the vibration in x,y,z directions should be same. So I think they may not mean the vibrations on x,y,z's direction.
Then, would any one like to tell me the meaning of them? I am really puzzled by this data~~~
Thanks.


--
GAO Zhe
CMC Lab, MSE, SNU, Seoul, S.Korea
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