Reducebf and bfcmt Method for Magnetic Calculation References

 

Muhammad Avicenna Naradipa - 2019-08-21

Dear All,

I'm working on manuscript on my previous AFM calculations and one of the reviews commented on the way I set up the magnetic spins in bfcmt.

The procedure I used is:
1. Set bfcmt in magnetic atoms to +/- 3.00
2. Set reducebf to 0.8

I've explained to them that the large spins are essentially to break up the spin symmetry and will eventually become infintesimal after more iterations (as this is the common procedure to speed up calculations from what I've gathered form the forums), but they commented that this would be highly correlated to the DFT+U I've already set. I assume this would not be a problem since I'm not actually "turning on" the spins and fixed it in that direction.

Are there any references regarding this method so I can confirm to them that this is standard procedure in Elk?

Best,
Cenna

 

• • 
    

J. K. Dewhurst - 2019-08-21

Hi Cenna,

In the more recent versions of Elk this trick is usually not needed any more.

However, you are quite correct that the bfcmt is reduced to zero. Unless the calculation has multiple fixed points, which is unlikely, it doesn't matter where you start from. Only the self-consistent solution matters and this found when the field is reduced to zero.

Regards,
Kay.

 

https://sourceforge.net/p/elk/discussion/897820/thread/6884917976/