[Wien] EFG + ETA calculation

[Marcelo Barbosa]

Dear Prof Blaha,

The biggest supercell I used for Ga2O3 was 1x3x2, which has 120 atoms.
Then I changed one of the Ga atoms to Cd and relaxed the atomic positions.

Since GGA+U or hybrids won’t affect the EFG and ETA in this case, do you think I should try bigger supercells?

Thank you very much for your help,
Marcelo

> On 03/02/2015, at 06:43, Peter Blaha <pblaha at theochem.tuwien.ac.at> wrote:
> 
> No, I don't think that for this system GGA+U or hybrids are appropriate.
> 
> Is your supercell large enough (~100 atoms) ??
> Did you relax the atomic positions ??
> Maybe the Cd sits in a different position ??
> 
> Am 02.02.2015 um 20:09 schrieb Marcelo Barbosa:
>> Dear all,
>> 
>> I need to calculate the EFG and ETA in a Cd impurity in Ga2O3 but using the usual GGA method gives me an ETA near 1 when experimentally it is known to be between 0.0 and 0.1.
>> I would like then to ask what is the best method to get good EFG and ETA values in such a case:
>> - use GGA+U for the 3d orbitals of Ga and 4d orbitals of Cd?
>> - use onsite-exact-exchange / hybrid functionals for those orbits?
>> - use hybrid functionals for all electrons?
>> or do you think these different options won’t change the ETA?
>> 
>> Best regards,
>> Marcelo Barbosa
>> _______________________________________________
>> Wien mailing list
>> Wien at zeus.theochem.tuwien.ac.at
>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>> SEARCH the MAILING-LIST at:  http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
>> 
> 
> -- 
> Peter Blaha
> Inst.Materials Chemistry
> TU Vienna
> Getreidemarkt 9
> A-1060 Vienna
> Austria
> +43-1-5880115671
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at:  http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html