Scf cycle in non-collinear magnetic system

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sponce
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Joined: Sat Apr 16, 2011 9:44 am

Scf cycle in non-collinear magnetic system

Post by sponce » Wed Jun 11, 2014 2:49 pm

Dear all,

I'm trying to converge a ground state scf cycle of a ferromagnetic compounds (containing half-filled Eu 4f electrons) taking into account SO coupling in PAW.

It's not converging:

Code: Select all

 ETOT  250  -932.41424563692     7.682E-01 3.847E-02 4.368E+02
 ETOT  251  -936.95319587233    -4.539E+00 8.552E-02 5.962E+02
 ETOT  252  -940.18025543856    -3.227E+00 3.904E+00 3.913E+02
 ETOT  253  -926.51020300340     1.367E+01 2.602E-01 9.431E+01
 ETOT  254  -926.75519625814    -2.450E-01 2.661E-02 8.302E+01
 ETOT  255  -932.57849535648    -5.823E+00 2.628E-01 3.813E+02
 ETOT  256  -926.55239654446     6.026E+00 1.684E-01 6.018E+01
 ETOT  257  -931.20513213756    -4.653E+00 2.538E-01 2.740E+02


Here are the relevant input variables:

Code: Select all

nline 20
kptopt    4       
ngkpt     4 4 4
nshiftk   1
shiftk    0 0 1/2
tolvrs1    1.0d-16
nstep1     1000
diemac1    4.0
iscf      17
nbdbuf    22
nband     *224
ntypat 5
znucl 63.0 56.0 14.0 8.0 7.0
usepawu   1
lpawu    3  -1  -1  -1   -1
upawu   7.5 0.0 0.0 0.0 0.0   eV
jpawu   0.6 0.0 0.0 0.0 0.0   eV
nsppol 1
nspden 4   # Non Colinear Magnetism
nspinor 2  # Non Colinear Magnetism
pawspnorb 1 # Spin-orbit coupling
spinat 0 0 7 66*0 # Impose magnetism
diemix 0.6
pawecutdg 60
ecut  30
ecutsm  0.5
ixc 11
paral_kgb 0


I have try the following (does not work)
- Change nline (from 4 to 20)
- use dmatpawu :

Code: Select all

dmatpuopt 2
usedmatpu  -3 # IMPOSE DENSITY MATRIX IN THE FIRST 10 STEPS
dmatpawu  1.0 0.0 0.0 0.0 0.0 0.0 0.0
          0.0 1.0 0.0 0.0 0.0 0.0 0.0
          0.0 0.0 1.0 0.0 0.0 0.0 0.0
          0.0 0.0 0.0 1.0 0.0 0.0 0.0
          0.0 0.0 0.0 0.0 1.0 0.0 0.0
          0.0 0.0 0.0 0.0 0.0 1.0 0.0
          0.0 0.0 0.0 0.0 0.0 0.0 1.0

          0.0 0.0 0.0 0.0 0.0 0.0 0.0
          0.0 0.0 0.0 0.0 0.0 0.0 0.0
          0.0 0.0 0.0 0.0 0.0 0.0 0.0
          0.0 0.0 0.0 0.0 0.0 0.0 0.0
          0.0 0.0 0.0 0.0 0.0 0.0 0.0
          0.0 0.0 0.0 0.0 0.0 0.0 0.0
          0.0 0.0 0.0 0.0 0.0 0.0 0.0

- Use diemixmag -4 (I also tried -2)

Does anyone have any ideas how what could be wrong?

Thank you

Samuel.

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