The error about repeating previous PRL result.

[postnikov]

The error about repeating previous PRL result.

These days, I repeat the calculation results of PRL 97,09201(2006).
My obtained magnetic moment per unit cell in the one-dimensional vanadium-benzene wire system is
about 0.55ub,however, the above PRL paper show the magnetic moment should be 1 ub unit cell.

Is it my own input file error,or the atk code itself?

Could someone give me some advice?

The input file is attached!

[zh]

1). You had better use a same exchange correlation functional with the one used in literature.
2). In the setup of initial spins of atoms, only the vanadium atom is required.

[postnikov]

1). You had better use a same exchange correlation functional with the one used in literature.
2). In the setup of initial spins of atoms, only the vanadium atom is required.

I have change the XC function into GGA, and the inital spin is set only for V, the

result is very similar to the previous calculation, ie, M is also 0.6 ub

 ATK developers could like to check this case for me?

[zh]

I also checked it using the  Atomistix ToolKit 11.2.2. The total magnetic moment is about 0.6 uB. The density of states gives a metallic ferromagnetism, rather than the half-metallic behavior. The pseudopotential of vanadium provided in the the code may be problematic, and it needs to be improved.

[Anders Blom]

@zh: Do not use ATK 11.2.2 for anything (or 11.2.1 or 11.2.0 for that matter). It contains bugs and has been replaced by 11.2.3.

@postnikov: The article reference in your first post is wrong, so I cannot check the original results.

[zh]

The reference:
Volodymyr V. Maslyuk et al, Organometallic Benzene-Vanadium Wire: A One-Dimensional Half-Metallic Ferromagnet, Phys. Rev. Lett. 97, 097201 (2006)

[Anders Blom]

Thanks, I also just found it via Google I will see if I can check the results. The basis set of V look ok at a first glance, but that's no guarantee.

[Anders Blom]

I can confirm ATK predicts a metallic ferromagnetic state. The DOS resembles that in the article (you need 200 kz-points or so) but the majority states are slightly shifted so there is finite DOS at the Fermi level.

This might be a basis set effect, the article uses a rather different basis set. Maybe with LDA+U things would change a bit in ATK? They try this in the article without seeing a major effect, but perhaps ATK needs it to shift the bands slightly? You can try this!

[postnikov]

I can confirm ATK predicts a metallic ferromagnetic state. The DOS resembles that in the article (you need 200 kz-points or so) but the majority states are slightly shifted so there is finite DOS at the Fermi level.

This might be a basis set effect, the article uses a rather different basis set. Maybe with LDA+U things would change a bit in ATK? They try this in the article without seeing a major effect, but perhaps ATK needs it to shift the bands slightly? You can try this!

How about the  magnetic moment?
Can you show your input file ?

[Anders Blom]

My Mulliken populations show Q(up)-Q(down) about 0.7, I'm just trying to wrap my head around if there is a factor of 2 for the Bohr magneton, as that would put it around 1.4 as in the article...?

Input attached; I also tried the hexagonal configuration they use in the article, but it makes no difference.

[postnikov]

My Mulliken populations show Q(up)-Q(down) about 0.7, I'm just trying to wrap my head around if there is a factor of 2 for the Bohr magneton, as that would put it around 1.4 as in the article...?

Input attached; I also tried the hexagonal configuration they use in the article, but it makes no difference.

This is my siesta calculation result.

Q(up)-Q(down) =0.9993

In my SIESTA calculation, V 3p is considered as the semicore state in the used PP and basis.

How about the ATK code?

[Anders Blom]

In the pp we have in ATK right now, 3p is pure core. You can try the SIESTA pp in ATK, as long as it's a UPF file with the right format and no off-diagonal projectors. You do however have to make a customized basis set then to include 3p. Not too hard, the pp is the tricky bit.

My DOS is similar, just shifted a bit. Is your majority DOS @ Ef zero or finite?

[postnikov]

In the pp we have in ATK right now, 3p is pure core. You can try the SIESTA pp in ATK, as long as it's a UPF file with the right format and no off-diagonal projectors. You do however have to make a customized basis set then to include 3p. Not too hard, the pp is the tricky bit.

My DOS is similar, just shifted a bit. Is your majority DOS @ Ef zero or finite?

The majority DOS @ Ef is zero, as shown in the above fig.

Could you provide the modified V pp and basis including 3p for me and other ATK users.

As you know, the Up-Down is about 0.6 or 0.7, it is very different from the result published in Phys. Rev. Lett. and the SIESTA code.

So if the modified V pp and basis are provided, the other people can also adopt them in their research work about V.

[Anders Blom]

Ok (was hard to tell if it was just small or zero). But the band edge is very close to Ef, closer than in the PRL I think, so I guess the V core/basis set matters a lot.

[postnikov]

Ok (was hard to tell if it was just small or zero). But the band edge is very close to Ef, closer than in the PRL I think, so I guess the V core/basis set matters a lot.

How about the PP and basis?