My Community

Hello,

I have researched about Hubbard U parameter of transition metal carbide or nitride

such as TiC, TiN, ZrC and so on.

However, there weren't any reference that calculated Hubbard U parameter of those materials.

I have read about transition metal carbide DFT papers and none of them indicated the Hubbard U parameter.

Meanwhile, there were plenty of reference about transition metal oxide U parameter.

So my question is, does transition metal carbide or nitride not need to use DFT+U method?

Thank you.

Dear Seunghwan_Kwon ,

Did you see this paper Phys. Rev. B 79, 235126 (2009)?
There is an extensive discussion on the U value in TiN.

In principle, DFT+U was proposed to improve the description of systems with strongly correlated d and f electrons. However, whether these correlation effects play an important role depends on the compound and the properties of interest.

You might find the discussion in this thread useful.

I am doing DFT calculations for zirconium carbide and

I have read about ZrC DFT papers, but there weren't any

Hubbard U parameters indicated.

So, I am still confused that no one wrote zrc hubbard u parameter.

Also, is it fine not to use U parameter for lattice parameter calculations and use it for just electronic?

I calculated zrc u parameter using linear response before but the band gap is 0 so verification of it is difficult and the lattice parameter is overestimated than pure dft.

Thank you

In transition metal oxides, the Hubbard correction is usually needed to correct the band gap or magnetic moments.
If you are interested in ZrC specifically, I would point out that ZrC is metallic and in metals the d-states are less localized and less correlated.
I would suggest that you resort to DFT+U if you get unsatisfactory results with DFT. Is that the case for you?