ABINIT Discussion Forums

Dear ABINIT users:

Using the Optic to calculate semiconductor dielectric function, epsilon, it always showed small negative imaginary (epsilon2) value at the low imput energy between 0 to 1.0eV. It should be equal zero when the input energy approach to 0eV.
Is there any way to resolve this problem?


Regards

Denny

I did found a similar problem, even by increasing the K points grid or the cutoff it remains and I did not find a way to go around. I did have to move to a
the dielectric calculation by using the GW approach. That gave me a much better agreement. Look at the GW tutorial and Matteo Giantomassi thesis,
there is a very nice description there!.

regards

-aldo

Dear aromero,

Thanks for your comment! Could you give us the website that can download Matteo Giantomassi thesis?

Denny, if you send me a private message to my email, I can copy it to you, otherwise you need to check on the web. He did his PhD with Xavier Gonze
at UCL (Louvain Belgium)

let me know if I can help

regards

Here is Matteo Giantomassi's thesis:

http://www.bictel.be/Record/Home?id=UCL ... n.be:22486