Re:Sites and atomic positions (in English)

Posted on : February 28, 2008 (Thu) 17:15:38

by akai

In order to get a better agreement with experiments concerning
band gaps, introducing the vacancy site is preferable.
zincblende lattice has a fcc Bravai lattice containing two atoms
per unit cell. If we add two additional vacancy sites, it has 4
atoms per unit cell.

For wurtzite structures, you may either with or without vacancy
sites. Introducing the extra vacances may give better results.


>Based on sample of (In,Mn)As provided by Prof. Akai in cpa2002v006d, the input file was written using extra empty muffin-tin potentials on the antibond site.
>Do I have to put the same extra empty muffin-tin potentials for wurtzite structure?
>And also about the atom positions, it was written only 4 atoms in the unit cell, but as I know that zinc-blende lattice has 8 atom in the unit cell. Why?
>Could somebody help me?
>
># Sample of(In,Mn)As provided by Prof. Akai
>go data/inmn6mn0as0as fcc 11.45,,,,,,
>0.001 1.4 nrl mjw mag 2nd
>update 4 40 0.024
>4
>InMn 4 1 0 2 49 94
> 25 6
> 25 0
> 33 0
>As 1 1 0 2 33 100
>Vc1 1 1 0 0 0 100
>Vc2 1 1 0 0 0 100
>4
>0.0 0.0 0.0 InMn
>0.25 0.25 0.25 As
>0.5 0.5 0.5 Vc1
>0.75 0.75 0.75 Vc2
>
>
># My input file for ZnO wurtzite structure
> go znvo25
> hcp 6.1404 1.60237 1.0 90.0 90.0 120.0
> 0.001 3.0 sra mjw mag
> 2nd update 4 100 0.020
> 2
> ZnV 3 1 0 2 30 75
> 23 25
> 23 0
> O 1 1 0 2 8 100
> 4
> 0.33333 0.66666 0.00000 ZnV
> 0.66666 0.33333 0.50000 ZnV
> 0.33333 0.66666 0.34500 O
> 0.66666 0.33333 0.84500 O