[Pw_forum] Raman spectra calculation for ZnO in the examples

[ＷＡＮＧ ＹＵＡＮＱＩＮＧ]

Drear all,

Hi. First of all, I want to thank Otani sensei. It helps.

Today, I examined the examples in PHonon/examples/examples15/. I found one problem about the calculation of raman spectra for ZnO. In the reference the file "zno.dm.out" writes:

# mode   [cm-1]    [THz]      IR
    1      0.00    0.0000    0.0000
    2      0.00    0.0000    0.0000
    3      0.00    0.0000    0.0000
    4      0.00    0.0000    0.0000
    5      0.00    0.0000    0.0000
    6      0.00    0.0000    0.0000
    7     47.34    1.4193    0.0000
    8    105.62    3.1664    0.0000
    9    157.77    4.7300    0.0000
   10    214.72    6.4370    0.0000
   11    276.27    8.2825    0.0000
   12    337.53   10.1189    0.0000

In this output I cannot find the intensity of Raman spectra. However, the plot program actually try to plot the raman intensity, as shown below:

  plot 'plotdata_zno.dat' u ($2):($3) title ' ZnO-RAMAN' w i lw 2

It puzzles me a a lot. Is the column $3 the Raman intensity? I think it is not.

Then, I tried to add "lraman=.true.," in the input for PHonon calculation. But it says "no elec. field with metals". 

Can anyone tell me how to get the raman intensity?

Thank you in advance.

Best regards,

Yuanqing Wang