problem in moemnt magnetic

Posted on : May 05, 2018 (Sat) 19:44:31

by houssine

Dear professor,
When I run the go program of my system GaN i made a doping with Cr element and co-doping with Cr and Co, for both situations I find the moment null and when I trace Total Dos it gives me symmetry,
which is magnetic it gives me a zero magnetic momment! I don't know why!
here is input on which I work thank you very much
c---------------------------------- 0 ----------------------------------
c now # can be used as comment lines as well
c--------------------------------------------
go data/GaN hcp 6.026714122776,1.625768217735,1.0,90.0,90.0,120.0,
0.001 1.2 sra gga91 mag 2nd
update 5 700 0.020
4
c--------------------------------------------
c name of type, number of components, rtr,
c field, lmax, atomic number, concentration
c--------------------------------------------
Ga 2 0 0.0 2 31 94
24 6
N 1 0 0.0 2 7 100
Vc_1 1 0 0.0 2 0 100
Vc_2 1 0 0.0 2 0 100
8
0.28867513 0.50000000 0.61291462 Ga
0.57735027 0.00000000 1.42579873 Ga
0.28867513 0.50000000 0.00000000 N
0.57735027 0.00000000 0.81288411 N
0.00000000 0.00000000 0.27096137 Vc_1
-0.00000000 0.00000000 -0.54192274 Vc_1
-0.28867513 0.50000000 0.33870171 Vc_2
0.28867513 -0.50000000 -0.47418240 Vc_2

Thank you for your help

[Re:04] problem in moemnt magnetic

Posted on : May 08, 2018 (Tue) 06:53:40

by houssine

Dear professor,
I use the input you give me but the calculation does not match

[Re:03] problem in moemnt magnetic

Posted on : May 06, 2018 (Sun) 18:30:15

by Administrator

Sorry you have to use "aux" instead of "prv".

go data/gan aux 0.8660254038 0.5 0 -0.8660254038 0.5 0 0 0 1.625768217735
6.026714122776
0.001 1.7 sra gga91 mag 2nd
update 2 100 0.010
........

KKR administrators

[Re:02] problem in moemnt magnetic

Posted on : May 06, 2018 (Sun) 18:06:14

by Administrator

I found another problem. Your hcp primitive unit cell vectors for seem 90 degree rotated from the standard definition around z-axis. The standard hcp unit cell vectors are taken as (1/2, -sqrt(3)/2, 0), (1/2, sort(3)/2, 0), and (0, 0, c/a). You have to change the atomic positions so as to fit the above. Alternatively, you can specify your own primitive unit cell vectors using "prv" instead of "hcp" as follows:

go data/gan prv 0.8660254038 0.5 0. -0.8660254038 0.5 0. 0. 0. 1.625768217735
6.026714122776
0.001 1.7 sra gga91 mag 2nd
update 2 100 0.010
4
c--------------------------------------------
c name of type, number of components, rtr,
c field, lmax, atomic number, concentration
c--------------------------------------------
Ga 2 0 0.0 2 31 94
24 6
N 1 0 0.0 2 7 100
Vc_1 1 0 0.0 2 0 100
Vc_2 1 0 0.0 2 0 100
8
0.28867513 0.50000000 0.61291462 Ga
0.57735027 0.00000000 1.42579873 Ga
0.28867513 0.50000000 0.00000000 N
0.57735027 0.00000000 0.81288411 N
0.00000000 0.00000000 0.27096137 Vc_1
0.00000000 0.00000000 -0.54192274 Vc_1
-0.28867513 0.50000000 0.33870171 Vc_2
0.28867513 -0.50000000 -0.47418240 Vc_2

However, we do not quite understand the meaning of the position for Vc's.

KKR administrators

[Re:01] problem in moemnt magnetic

Posted on : May 06, 2018 (Sun) 14:48:35

by Administrator

It is important to use a rather wide energy window. The point is Ga d level that located deep below the Fermi energy should be completely covered by the energy contour. Try the following input file. bzqlty=3 would be sufficient for convergence. If you would like to get better quality, you may increase bzqlty later. If you got any problem about convergence, firs calculate with Cr concentration being 0, and after convergence, switch to a finite concentration. pmix=0.01 is suitable for this system.

KKR administrators

c------------- input for (Ga0.94Cr0.06)N
go data/GaN hcp 6.026714122776,1.625768217735,1.0,90.0,90.0,120.0,
0.001 1.6 sra gga91 mag 2nd
update 3 100 0.010
4
c--------------------------------------------
c name of type, number of components, rtr,
c field, lmax, atomic number, concentration
c--------------------------------------------
Ga 2 0 0.0 2 31 94
24 6
N 1 0 0.0 2 7 100
Vc_1 1 0 0.0 2 0 100
Vc_2 1 0 0.0 2 0 100
8
0.28867513 0.50000000 0.61291462 Ga
0.57735027 0.00000000 1.42579873 Ga
0.28867513 0.50000000 0.00000000 N
0.57735027 0.00000000 0.81288411 N
0.00000000 0.00000000 0.27096137 Vc_1
-0.00000000 0.00000000 -0.54192274 Vc_1
-0.28867513 0.50000000 0.33870171 Vc_2
0.28867513 -0.50000000 -0.47418240 Vc_2