[Wien] Find a -2.48Ry level for Ga 3d.

[Lyudmila Dobysheva]

On Friday 16 June 2006 08:29, liyh wrote:
> When we calculate a superlattice of  GaN/InN we find the Ga 3d  always find
> a -2.48Ry energy level and got a ghost band. But when we reduce the lattice
> from 24 atoms to 8 atoms, the problem is disappeared. We also reduce the
> mxing parameter to 0.01, but the problem is still. Could you tell me why
> and how to resolve it?

Did you try what I have suggested in the letter of 07/04/06 :
---------------
to have for Ga atoms in case.in1 something like:
  0.30    4  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global APW/LAPW)
 2   -0.29      0.000 CONT 1  <--- do not allow to search energy
 2    1.00      0.000 CONT 1
 0    0.30      0.000 CONT 1
 1    0.30      0.000 CONT 1
Maybe to play a little with these two energies for d-band.
---------------

In your letter of April I see that these ciphers around -2Ry appeared not from 
_finding_   the Ga 3d, but from   _not_finding_   anything:

>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga1
>           E( 2)=    0.6750   E(BOTTOM)=    0.540   E(TOP)=    0.810
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga2
> ----> E( 2)=    2.0500   E(BOTTOM)=    2.050   E(TOP)= -200.000 <----
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga3
> ----> E( 2)=    2.5700   E(BOTTOM)=    2.570   E(TOP)= -200.000 <----
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga4
> ----> E( 2)=    2.3100   E(BOTTOM)=    2.310   E(TOP)= -200.000 <----
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga5
> ----> E( 2)=    1.5700   E(BOTTOM)=    1.570   E(TOP)= -200.000 <----
>           ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ga6
>           E( 2)=    0.3150   E(BOTTOM)=    0.180   E(TOP)=    0.450

As far as I understand, Ga has a 3d level too close to the valence band 
-0.7 Ry - -0.4 Ry with valence band starting at -0.2 Ry - -0.1 Ry. The valence 
band always contains d states, also. It seems to me that, in some systems, 
the program cannot find for Ga the localized level 3d at the background of 
the wide valence band. So, one may occasionally have problems with it, as you 
have had with AlN/GaN and now with GaN/InN. 
So, better not allow to search energy, and adjust it by hand, after some 
cycles of iterations. 

Best regards
  Lyudmila Dobysheva 
------------------------------------------------------------------
Phys.-Techn. Institute of       | Tel.(home):   7 (3412) 442118
Ural Br. of Russian Ac. of Sci. | Tel.(office): 7 (3412) 218988
426001 Izhevsk, ul.Kirova 132   | Fax:          7 (3412) 250614
RUSSIA                          | E-mail: lyu at otf.fti.udmurtia.su
------------------------------------------------------------------
http://fti.udm.ru/ltt/personals/dobysh.htm
------------------------------------------------------------------