[Wien] Eigen values

[sudha sankaran]

Dear Sir,
I have plotted the band structure for CdS Zincblende. Even though the exact 
band gap is 2.2ev, Iam getting the gap as ~1.2ev. What can I do to improve 
this?I would also like to know where i can find the eigen values (which 
file). I have to do a fourier transform of these eigen values for my CdS 
nanostructure calculations. Please let me know.
Thanking you
Sudha Sankaran,
Department of Physics,
IIT- Delhi