QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: berna on March 23, 2017, 13:30

Title: Hubbard-U Term, Spin Polarization and Geometry Optimization
Post by: berna on March 23, 2017, 13:30

Hi.
If we use Hubbard-U parameter (LDA-U, GGA-U) for dft calculation, should dft for  geometry optimization include Hubbard-U parameter?
Similar as above,  if we use spin polarization for dft calculation, should dft for  geometry optimization include  spin polarization?

Title: Re: Hubbard-U Term, Spin Polarization and Geometry Optimization
Post by: Jess Wellendorff on March 23, 2017, 15:00

Depends on the system, but one does not in general use DFT-U for geometry optimization. On the contrary, including the spin-polarization in geometry optimization of a ferromagnetic material like iron is crucial.

Title: Re: Hubbard-U Term, Spin Polarization and Geometry Optimization
Post by: Kim_W on December 3, 2017, 06:57

1. NO, NO2, and O2 are paramagnetic, should dft for  geometry optimization include spin-polarization?
2. If we calculate heavy elements, should dft for  geometry optimization include spin-polarization?

Title: Re: Hubbard-U Term, Spin Polarization and Geometry Optimization
Post by: Daniele Stradi on December 4, 2017, 09:13

Yes, in principle the geometry optimization and electronic structure calculation on the optimized geometry should be done at the same level of theory