Rare earth

Message

Kitaura · #1 Post by **Kitaura** » Fri Jan 02, 2009 6:07 am

Dear vasp users,

I'm working on band structure calculation of compounds containing rare earth metals.
I have a question on PPs treating f-orbital as a core.

When I calculate, for example Gd compounds possessing 4f7 electronic configuration with PPs treating f-orbital as a core, should I perform the calculation using ISPIN=2 (spin polarized system) ? I think if I use PPs treating f-orbital as valence, I should definitely set ISPIN =2. But in this case, what should I do ?

any comments and advices are greatly appreciated.

Thanks in advance

#2 Post by **admin** » Thu Jan 08, 2009 3:07 pm

This of course depends on the compound and the valence electron configuration of its atoms. Staying with your Gd example: even if you use the PP which puts the f-electrons into tthe core, you have 1 unpaired 5d electron. --> in this case, please use ISPIN=2

wangfei · #3 Post by **wangfei** » Mon Feb 16, 2009 7:11 pm

Hi admin,

What if I use Gd_3 in the calculation of a compound such as Gd5Ge4? Since the f electrons are in the core in Gd_3, do I still have to use ISPIN=2 for the unpaired 5d electron?

#4 Post by **admin** » Tue Feb 17, 2009 11:19 am

yes, of course

wangfei · #5 Post by **wangfei** » Thu Feb 19, 2009 5:39 pm

Thank you for the reply, admin!
I still have one more question about this unpaired 5d electron. In a compound, this electron can be paired with the valence elecron from another atom (for my case, with a 4p electron from Ge). So if I use ISPIN=1, it still makes sense. Am I right?
<span class='smallblacktext'>[ Edited Thu Feb 19 2009, 06:46PM ]</span>