QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: rightsuman on September 11, 2017, 19:08

Title: crystal field splitting
Post by: rightsuman on September 11, 2017, 19:08

In some papers we see crystal field splitting shown in Density of states plot. for example : splitting of Cr to t2g and eg in Sr2CrO4. The paper link is given below.
https://arxiv.org/pdf/1511.06217.pdf
Can this be performed in ATK?
If yes how?

Title: Re: crystal field splitting
Post by: Daniele Stradi on September 12, 2017, 09:40

Could you please state which exact figure are you referring to? The DOS analysis carried out in the paper can be done using the new ProjectedDensityOfStates, available in ATK 2017:

https://www.youtube.com/watch?v=6lw3nurLCcg

Regards,

Daniele.

Title: Re: crystal field splitting
Post by: rightsuman on September 13, 2017, 15:50

I was referring to figure 4a nad 4b of the paper. In the video it does give the contribution of atomic orbitals but not the crystal field splitting shown in these two figures.

Title: Re: crystal field splitting
Post by: Daniele Stradi on September 13, 2017, 17:09

The way they calculate the crystal field splitting is by projecting the local density of states onto the d-orbitals with the relevant symmetry:

t2g = d_{xy}, d_{xz}, d_{yz}
eg = d_{z2}, d_{x2-y2}

Therefore, to calculate the projection on the t2g manifold, you simply have to sum up the projections on the d_{xy}, d_{xz}, d_{yz} orbitals. However, this cannot be done in VNL, only by scripting by querying the ProjectedDensityOfStates object using evaluate():

https://docs.quantumwise.com/manuals/Types/ProjectedDensityOfStates/ProjectedDensityOfStates.html

Regards,
Daniele.