I tried to calculate the Raman spectra of alpha-Al2O3 following the tutorials, you can find my input file in the attachment.
al2o3-nlo-alfa.in- main input file
- (2.81 KiB) Downloaded 365 times
The phonon frequencies consist with the available results very well, but the Raman susceptibilities do not obey the symmety. The Raman active Mode Eg, which Raman tensor should look like
[c 0 0] [ 0 -c -d]
[0 -c d] or [-c 0 0].
[0 d 0] [-d 0 0]
However, the calculated Eg tensors of 376 cm^(-1) mode are
[-0.000003129 -0.000001740 -0.000308830] [-0.000001740 0.000003129 -0.000171767]
[-0.000001740 0.000003129 0.000171767] or [0.000003129 0.000001740 -0.000308830]
[-0.000308830 0.000171767 0.000000000] [-0.000171767 -0.000308830 0.000000000]
Actually, all calculated Eg Raman tensors break the symmety.
- al2o3-nlo-ana.out
- anaout file
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I am not sure this is a bug in abinit-6.12.2, since the Raman tensors of Ag mode follow the symmety obtained in the same calculations.
I just want to know what happen there. Please help me with it. Thank you in advance.
PS: you can also find the ddb and anaout files in the attachment