Bandstructure by using DFT+U

[hadi9827]

Dear ATK staff,

I am trying to calculate the ZnO bandstructure by using the GGA PBE + U method as it has been done in this paper: Ferromagnetism properties of Er-doped ZnO:a GGA +Ustudy (https://doi.org/10.1039/C6RA17921E)
I changed the lattice parameters to a=3.32 and c=5.34 which are the optimized numbers in the paper and selected 7 eV and 10.5 eV as U for oxygen and zinc atoms. Everything is similar to the ones in the paper but I can not calculate the bandstructure and the bandgap is 0 for my calculations. I attached the script and the log and the result. Would you please help me solve this problem?

Thanks.

[mlee]

The reference used Planewave. If you run in LCAO + GGA, U parameter should be optimized. It will be different U parameter from the U in Planewave.

[hadi9827]

Thank you very much for your response. How should I do that? I mean how can I make a good guess for the beginning? I am totally blind for starting with what quantities of U and for what orbitals
Thanks

[hadi9827]

I checked several papers and all of them use plane wave, but as far as I know, U correction is not possible for the plane wave method in ATK. What do you suggest me to do? thanks.

[mlee]

QuantumATK can use U parameter in LCAO. If you have a reference band structure, you can fit it changing the U parameter in LCAO.