QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: davalenciah on April 15, 2014, 23:45

Title: Band structure GaAs Huckel
Post by: davalenciah on April 15, 2014, 23:45

Hello guys,

I am interested in getting the band structure for GaAs using extended Huckel and Cerda-GW parameters; I calculated an energy gap of 1.203 eV, which is significantly lower than the experimental value. Do you have any idea what might cause this error?

Thank you

Title: Re: Band structure GaAs Huckel
Post by: Anders Blom on April 17, 2014, 10:39

Not immediately, no. We'll have a closer look after Easter.

Title: Re: Band structure GaAs Huckel
Post by: davalenciah on April 23, 2014, 20:38

Hi Dr Blom,

Have you had a chance to look at why the value of energy value for GaAS with Extended Huckel method  is different than empirical values?


Thank You

Title: Re: Band structure GaAs Huckel
Post by: Anders Blom on April 30, 2014, 17:21

The Cerda "GW" parameter sets are not fitted to experiments, they are fitted to GW, and I guess 1.2 eV is what GW gives for GaAs. The "Cerda [GaAs]" set is fitted to experiments and gives 1.47 eV.

Title: Re: Band structure GaAs Huckel
Post by: davalenciah on May 1, 2014, 03:07

Thank You so much for Your answer Dr Blom.