DFT+U refers to a general method to describe localized electrons. GGA+U is a specific case of DFT+U, where the underlying exchange-correlation functional is GGA (like PBE+U).
Example: DFT+U can be a general term referring to GGA+U, LDA+U, etc.
In summary, GGA+U is a type of DFT+U.
Almost same, but specifically GGA+U should be the way to go unless you also added LDA+U in your caculation. DFT+U can be LDA+U or GGA+U or both, there is somewhat different in exchange functional Approximation.
Sir, Could you provide me with any SCF.in file with applying GGA+U?
Which code you use?
If you are familiar with Quantum espresso
Examples are there within PW folder.
The correct way to deploy Hubbard potential is to generate by yourself within the framework of DFPT /linear response( in Quantum espresso, using hp code , you can calculate your U (onsite Hubbard) and V(intersite Hubbard) for your system.
Basically, U and V values are not universal, you can not take from literature. Since those potential depend on many factors like your system, structure, pseudopotential, whether paw or ultrasoft or norm-Conserving psp. And also, the projection you opted for Hubbard projection.
The input scf.in should look like
&Control
/
& System
/
& Electrons
/
& Atomic Species
/
& Atomic_Position
/
& K_Point
/
& Hubbard(ortho-atomic)->projection you want)
U Co-3d **
U Fe-3d **
Yes, I used Quantum espresso. I used the running code is hp.x < SCF.in > SCF.out. Why do we apply GGA+U? what is the expected result after GGA+U?
Mainly, to overcome self interaction error that is in order to correct electron-electron interaction in strongly correlated system or d, f electrons
For p system we generally don't consider U value
They are the same description as the whole-part relationship. DFT+U remains in the whole relationship, and inside it, there are several functions, such as GGA+U, PBE+U, etc. When you say DFT+U directly, I will assume you are using one of these functions (GGA+U, PBE+U, etc.).
- Badges
- Science topic
- Similar topics
- Analytical Chemistry
- Extraction