# How do I get exact percentage of spin-polarization in Quantum ESPRESSO?

Cross-posted on ResearchGate

I am investigating a near half-metallic / high-spin polarization material. I ran an SCF calculation with nspin = 2, with some starting magnetization. So now I wonder how to find the exact percentage of spin-polarization (%SP). I have already done PDOS calculation, and from that I can clearly "see" it's nearly half-metallic, but I don't know how to extract the %SP.

Is it mentioned somewhere in the output file after the SCF, or do I need it to extrapolate it somehow? Please help. Thank you!

• +1 Excellent first question! Hopefully you'll get a quick answer! Welcome to our new community and thank you for contributing your question here. We hope to see much more of you in the future !!! I made some minor edits, including using the code block for your code. Feb 20 at 0:38
• Thank you, Nike! Feb 26 at 10:55

The estimate of the net electronic spin polarization is calculated using the up and down DOS values at the Fermi level using the following expression:

$$\mathrm{Spin \ polarization}= \frac{ABS(DOS_{UP}-DOS_{DOWN})}{(DOS_{UP}+DOS_{DOWN})}.\tag{1}$$

This has been taken from this post on ResearchGate.

• +1. It's great to see this question from 2 months ago get an answer, and this was a perfect use of the Community Wiki feature! May 16 at 21:56
• @NikeDattani Thanks! But the thing is, the question on Research Gate was posted by the same person; The question is copied verbatim. The sad part however is that the person received an answer in February and didn't quite add it in. May 17 at 14:06
• Thanks for bringing that to our attention. I hadn't noticed that, we'll consider what to do about it in this case. May 17 at 15:11
• I looked at this in more detail now. The user posted the question here on 20 February, then posted it on ResearchGate on 26 February because they didn't get an answer here. They got an answer quickly on ResearchGate then never signed back into MMSE ("last seen on 26 Feb"). Ideally users will let us know when they've cross-posted something, and they will let us know when they've got an answer, but we can't expect that from everyone (especially new and infrequent users). May 17 at 16:10
• Well, if the system is a semiconductor, the Fermi level will be in the gap, so, there are no available states, and the calculation will return $\infty$.
– Camps
May 17 at 16:55