Spin-Orbit calculation for a non magnetic state ( The example of GaAs )

This titurial is prepared according to the video made by Mr Oleg Rubel one of the developpers of Wien2k

We will mix between the w2web interface and the terminal.

* Create the working directory and change to it

$ mkdir GaAs-So

$ cd GaAs-So/

GaAs-So $

* Using w2web interface, create the struct file GaAs-So.struct using these data:

a=b=c= 10.683 a.u  F lattice

Ga (0.0.0)
As (1/4,1/4,1/4)

* Initialisation with these parameters using w2web interface in expert mode:

PBE, RKmax= 7, Kpoint= 800 Rmt reduction= 2%

 * Scf calculation using terminal

GaAs-So $ run_lapw  ---> without spin-orbit (SO) coupling

The calculation converges after 7 iterations

* Now we include the SO coulpling

GaAs-So $ initso_lapw  ---> SO initialization

• Default 001 direction
• Enter (default none)
• 5 (default 5.0 Ryd)
• a (All)
• N (for non-polarized case)

* Now we do SO calculation

GaAs-So $ rm *.bro*

GaAs-So $ run_lapw -so

The calculation converges after only 3 ietrations

* Now we plot the band structure

- We use the XCrysDen tool to create the GaAs-So.klist_band file

- In terminal we do the following commands:

GaAs-So $ x lapw1 -band

GaAs-So $ x apwso

GaAs-So $ grep :FER *scf2  ---> to get the fermi level 

- Continue with w2wen and include the value of fermi level and calculate the band structure.

- Plot the band structure using a suitable scale.

* You will get this picture for band structure

You can check this video made bu Mr Rubel Oleg