Deals with issues related to computation of optical spectra, in RPA (-o c) or by solving the Bethe-Salpeter equation (-o b). Includes local field effects, excitons, etc.

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Post by haseebphysics1 » Tue Aug 25, 2020 11:25 pm

Dear Daniele,

I have repeated a TDDFR LRC after a long time with different alpha value, but on the same database with the same version of the code. However, the headers of the two output files are quite different, and in particular, I am confused, whether the data is of absorption coeff. (alpha) in one of them or imaginary part (as usual)? Two output files are attached.

Code: Select all

# Absorption @ Q(1) [q->0 direction] : 0.5773503  0.5773503  0.5773503
# Polarizability ( -<<X>> ) [adim @ Q(1) [q->0 direction] 0.5773503  0.5773503  0.5773503
#    E/ev[1]       EPS-Im[2]     EPS-Re[3]     EPSo-Im[4]    EPSo-Re[5]
#    E/ev[1]       ALPHA-Im[2]   ALPHA-Re[3]   ALPHAo-Im[4]  ALPHAo-Re[5]

can you please spot the issue here?

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Haseeb Ahmad
MS - Physics,
LUMS - Pakistan

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Daniele Varsano
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Post by Daniele Varsano » Thu Aug 27, 2020 8:44 am

Dear Haseeb,
no, it is not clear to me why you have the header including alpha, as this should me dumped in the o.alpha file.
The only difference I can spot from the two file is the use of the parallel linear algebra, but this should not cause this.
Most probably the result is the absorption (eps) as named in the output file: o*.eps*

Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale

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