error real space spin density difference of Right electrode after ts calculation at 0 bias
Dear all:
I calculate the transport property of graphyne nanoribbons at antiparallel spin configuration. Analysis of "Rho.grid.nc" of the Scattering Region, I found real space spin density difference of the Right electrode is totally different form that of the right electrode bulk . I don't know the reason. Can someone give me some advice? My fdf file of the SR as follow:
>>>>>>>
SystemName z4 # Descriptive name of the system
SystemLabel z4 # Short name for naming files
# Output options
#WriteCoorStep 1
WriteMullikenPop 1
WriteDenchar T # Write information for DENCHAR
# Species and atoms
NumberOfSpecies 2
NumberOfAtoms 288
%block ChemicalSpecies
1 6 C
2 1 H
%endblock ChemicalSpecies
%block kgrid_Monkhorst
1 0 0 0.0
0 1 0 0.0
0 0 6 0.0
%endblock Kgrid_Monkhorst
LatticeConstant 1.0 Ang
%block LatticeVectors
58.399550000000000 0.000000000000000 0.000000000
0.000000000000000 30.000000000000000 0.000000000
0.000000000000000 0.0000000000000000 62.83239471
%endblock LatticeVectors
#%block AtomicCoordinat
#0.0 0.0 -13.9627543800
#%block AtomicCoordinat
xc.functional LDA # Exchange-
xc.authors CA # Exchange-
SpinPolarized T # Logical parameters are: yes or no
MeshCutoff 300. Ry # Mesh cutoff. real space mesh
# SCF options
MaxSCFIterations 60 # Maximum number of SCF iter
DM.MixingWeight 0.1 # New DM amount for next SCF cycle
DM.Tolerance 1.d-4 # Tolerance in maximum difference
DM.UseSaveDM T # to use continuation files
DM.NumberPulay 6
ElectronicTempe
# AtomionicTemper
AtomicCoordinat
%block AtomicCoordinat
16.10000000 15.00000000 1.74534000 1 1
16.10000000 15.00000000 8.72671719 1 2
16.79975000 15.00000000 2.95735000 1 3
16.79975000 15.00000000 9.93872719 1 4
..........
34.93790000 15.00000000 62.29905752 1 286
15.00000000 15.00000000 50.61498033 2 287
15.00000000 15.00000000 57.59635752 2 288
%endblock AtomicCoordinat
#######
####transiesta
SolutionMethod transiesta
%include NEW.fdf
TS.SaveHS true
>>>>>>>
NEW.fdf
>>>>>>>
TS.Voltage 0.00000 eV
TS.ElectronicTe
%block TS.ChemPots
Left
Right
%endblock TS.ChemPots
%block TS.ChemPot.Left
mu V/2
contour.eq
begin
c-Left
t-Left
end
%endblock TS.ChemPot.Left
%block TS.ChemPot.Right
mu -V/2
contour.eq
begin
c-Right
t-Right
end
%endblock TS.ChemPot.Right
TS.Elecs.Bulk true
TS.Elecs.DM.Update cross-terms
TS.Elecs.GF.ReUse true
%block TS.Elecs
Left
Right
%endblock TS.Elecs
%block TS.Elec.Left
HS ../../.
chem-pot Left
semi-inf-dir -a3
elec-pos begin 1
used-atoms 64
%endblock TS.Elec.Left
%block TS.Elec.Right
HS ../../.
chem-pot Right
semi-inf-dir +a3
elec-pos end -1
used-atoms 64
%endblock TS.Elec.Right
TS.Contours.Eq.Pole 2.50000 eV
%block TS.Contour.c-Left
part circle
from -40.00000 eV + V/2 to -10. kT + V/2
points 40
method g-legendre
%endblock TS.Contour.c-Left
%block TS.Contour.t-Left
part tail
from prev to inf
points 10
method g-fermi
%endblock TS.Contour.t-Left
%block TS.Contour.c-Right
part circle
from -40.00000 eV - V/2 to -10. kT - V/2
points 40
method g-legendre
%endblock TS.Contour.c-Right
%block TS.Contour.t-Right
part tail
from prev to inf
points 10
method g-fermi
%endblock TS.Contour.t-Right
TS.Elecs.Eta 0.0001000000 eV
%block TS.Contours.nEq
neq
%endblock TS.Contours.nEq
%block TS.Contour.nEq.neq
part line
from -|V|/2 - 5 kT to |V|/2 + 5 kT
delta 0.01 eV
method mid-rule
%endblock TS.Contour.nEq.neq
# TBtrans options
TBT.Elecs.Eta 0.0001000000 eV
%block TBT.Contours
neq
%endblock TBT.Contours
%block TBT.Contour.neq
part line
from -2.00000 eV to 2.00000 eV
delta 0.01000 eV
method mid-rule
%endblock TBT.Contour.neq
>>>>>>>
Question information
- Language:
- English Edit question
- Status:
- Solved
- For:
- Siesta Edit question
- Assignee:
- No assignee Edit question
- Solved by:
- 翟明星
- Solved:
- 2020-11-24
- Last query:
- 2020-11-24
- Last reply:
- 2020-11-24
Nick Papior (nickpapior) said : | #1 |
Are you sure the systems converged correctly? And that the TS cycle retained charges?
翟明星 (mxzhai) said : | #2 |
The TS cycle in outfile as follow:
>>>>>>>
iscf Eharris(eV) E_KS(eV) FreeEng(eV) dDmax Ef(eV) dHmax(eV)
ts-scf: 1 -41864.557886 -41864.549465 -41864.549465 0.000158 -4.496750 0.004871
spin moment: S , {S} = 0.87055 0.0 0.0 0.87055
timer: Routine,
ts-q: D E1 C1 E2 C2 dQ dQtot
ts-q: 301.193 118.617 3.668 118.617 3.647 4.258E-1
ts-q: 301.435 118.024 3.691 118.024 3.701 -4.512E-1 -2.537E-2
ts-Vha: 0.14379E-01 eV
ts-scf: 2 -41864.031327 -41864.291083 -41864.291083 0.001881 -4.496750 0.131296
spin moment: S , {S} = 0.87699 0.0 0.0 0.87699
ts-q: D E1 C1 E2 C2 dQ dQtot
ts-q: 301.200 118.617 3.667 118.617 3.650 4.354E-1
ts-q: 301.448 118.024 3.690 118.024 3.703 -4.361E-1 -6.489E-4
ts-Vha: 0.11872E-01 eV
ts-scf: 3 -41864.791319 -41864.541493 -41864.541493 0.001804 -4.496750 0.000957
spin moment: S , {S} = 0.87146 0.0 0.0 0.87146
ts-q: D E1 C1 E2 C2 dQ dQtot
ts-q: 301.200 118.617 3.667 118.617 3.650 4.356E-1
ts-q: 301.448 118.024 3.690 118.024 3.703 -4.362E-1 -6.326E-4
ts-Vha: 0.11861E-01 eV
ts-scf: 4 -41864.540831 -41864.541162 -41864.541162 0.000009 -4.496750 0.000847
spin moment: S , {S} = 0.87175 0.0 0.0 0.87175
>>>>>>>
By comparing the reference, the transmission is right. And the spin magnetic moment of atoms in device region is right.
Nick Papior (nickpapior) said : | #3 |
That looks fine.
How did you compare the charge?
翟明星 (mxzhai) said : | #4 |
I calculate the Mulliken population and Rho. I'm just making a rough comparison. In the device region, spin density at every atom around is right. But the spin polarization direction of right electrode part in ts calculation is opposite direction of the bulk right electrode. And spin density of the interface between electrode and SR is a little mix. So I think that maybe some setup is incorrect in my calculation. I tried some parameter such as: TS.poission and TS.ChargeCorrec
Nick Papior (nickpapior) said : | #5 |
Do you have different initial spin configurations in your leads?
Because that may be a bit difficult to enforce in TS calculations.
If you want to ensure that the charge-density and electrode density is consistent with the electrodes you should ensure that the *TSDE files for the electrodes are also present.
Then add this
TS.Elecs.DM.Init bulk
This will copy in the electrode density matrix directly into the electrode blocks. But please note that this will probably disrupt the SCF cycles and forces you to really be careful in your calculations.
You may aid SCF by having some buffer atoms where the spin is slowly rotating so that they match both electrodes (also not easy).
翟明星 (mxzhai) said : | #6 |
Yes. magnetization direction of Left lead is spin up, and that of right lead is spin down.
Thank you! I will try.
I have another question. Is my previous charge density in ts calculation correct?
Nick Papior (nickpapior) said : | #7 |
What do you mean?
I would say if you don't have the same spin-configuration in the leads you will have some trustworthy problems... :(
翟明星 (mxzhai) said : | #8 |
Ok. Thanks a lot.