Subject: Band gap problem

From: Arnold Alguno <[email-masked]>
Date: Tue, 10 Apr 2001 19:33:45 +0800 (PHT)

Dear CCLers,

I am calculating the energy band gap of Bithiophene using DFT functionals
- BLYP, B3LYP, B3P86. According to Lathti, P. M., Obrzut, J., Karasz, F.
E., Macromolecules, 1987, 20, 2023, the energy band gap is 2.7eV. In my
result i got 2.68, 4.06, 4.10 eV, repectively. Why is it that BLYP gives
an answer near to experimental value while the hybrid functionals
overestimates the energy band gaps?

Your answer and any suggestions to this problem are highly
appreciated. Thank you.

_________
Very truly yours,

ARNOLD C. ALGUNO
IITHEP, Department of Physics
MSU-IIT, Iligan City Philippines
[email-masked]
Mobile Phone & Text No.:+63-919-427-8205