BSE tutorial - WFK vs. KSS and strange results

nnikola · Post by **nnikola** » Thu Apr 16, 2015 12:42 pm

Hi all,

I have tried to walk through the BSE tutorial (using abinit 7.8.2).
I followed the prescriptions from tutorial and succesfully performed step 1. When I tried to perform actual BSE calculation (step 2), program stopped after it was unable to find tbs_2i_WFK file. After I have added tbs_2i_WFK link to tbs_1o_DS3_WFK, program successfully performed the calculations. The result was however different from the one presented in tutorial, with some oscillatorybehavior of Im(epsilon) starting at approx. 3.5 eV. The same Im(epsilon) oscillatory behavior was repeated in convergence studies as well.
Does anyone knows what can be the cause?

Also, it turned out that KSS reading directive is not really needed and that reading
SCR (with irdscr command)
and WFK (without irdwfk? --> BSE (optdriver 99) needs it by default??)
is sufficient. If so, tutorial should be changed...

Best regards,

Nikola