negative real part of 2D macroscopic polarizability

[lldu]

Dear Yambo developers,
I have done a 2D BSE calculation, but get negative real part of Alpa as shown in the following, which seems weird. Can you give me some advice about this?

# E/ev[1] ALPHA-Im[2] ALPHA-Re[3] ALPHA_o-Im[4] ALPHA_o-Re[5]
#
0.00000000 0.486273843E-1 -0.839697686E-1 0.719844600E-1 1.24373264
0.200400802E-1 0.518231437E-1 -0.774459138E-1 0.737027767E-1 1.25822689
0.400801603E-1 0.561164132E-1 -0.711091265E-1 0.754840099E-1 1.27306665
0.601202405E-1 0.615730240E-1 -0.652665423E-1 0.773312935E-1 1.28826452
0.801603206E-1 0.680915283E-1 -0.603412200E-1 0.792479602E-1 1.30383371
0.100200401 0.752682484E-1 -0.567136292E-1 0.812375567E-1 1.31978812
0.120240481 0.824606173E-1 -0.544129842E-1 0.833038607E-1 1.33614233
0.140280561 0.892064539E-1 -0.529576319E-1 0.854508991E-1 1.35291167
0.160320641 0.956585185E-1 -0.517352571E-1 0.876829682E-1 1.37011228

[Daniele Varsano]

Dear lldu,
please sign your posts with your name and affiliation, this is a rule of the forum and you can do once for all by filling your signature in the user profile.
In order to spot the problem, we need more information, can you attach your input and report files? (you can attach them by renaming e.g. with .txt suffix).

Best,
Daniele