Author Topic: Band structure GaAs Huckel  (Read 3624 times)

0 Members and 1 Guest are viewing this topic.

Offline davalenciah

  • Heavy QuantumATK user
  • ***
  • Posts: 26
  • Reputation: 0
    • View Profile
Band structure GaAs Huckel
« 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

Offline Anders Blom

  • QuantumATK Staff
  • Supreme QuantumATK Wizard
  • *****
  • Posts: 5575
  • Country: dk
  • Reputation: 96
    • View Profile
    • QuantumATK at Synopsys
Re: Band structure GaAs Huckel
« Reply #1 on: April 17, 2014, 10:39 »
Not immediately, no. We'll have a closer look after Easter.

Offline davalenciah

  • Heavy QuantumATK user
  • ***
  • Posts: 26
  • Reputation: 0
    • View Profile
Re: Band structure GaAs Huckel
« Reply #2 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

Offline Anders Blom

  • QuantumATK Staff
  • Supreme QuantumATK Wizard
  • *****
  • Posts: 5575
  • Country: dk
  • Reputation: 96
    • View Profile
    • QuantumATK at Synopsys
Re: Band structure GaAs Huckel
« Reply #3 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.

Offline davalenciah

  • Heavy QuantumATK user
  • ***
  • Posts: 26
  • Reputation: 0
    • View Profile
Re: Band structure GaAs Huckel
« Reply #4 on: May 1, 2014, 03:07 »
Thank You so much for Your answer Dr Blom.