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The Divergence of graphene calulcation in ESM model (ON2, M|V|M)
Date: 2017/01/09 19:09
Name: Kylin

Dear all
Currently I tested the property of Graphene or its derivative between two metal electrode surface via ESM model. However for the ON1 and ON3 cases, the SCF loop could convergent easily. However for the ON2 case, namely the graphene sheet is sandwiched by two metal electrode. The divergent of the total energy arise with the increase of the super-cell size.

I ever tested the size of C4 and C8 with different Y length. Both become convergent smoothly. however once the C12 or more carbon was added into the supercell, the energy in SCF loops diverged over the calculation.

I guess the problem may attribute to the high aspect ration in y and z direction and the correlation between to two metal electrode wall. However I cannot figure out what extra configuration or effort should be taken to overcome this problem in large atom cases.


Thanks for any help in advance

Kylin

--------------- C12 Case ----------------

#
# OpenMX Inputfile
#
# File Name
#
System.Name graphene
System.CurrrentDirectory ./
DATA.PATH ../../DFT_DATA13
# Definition of Atomic Species

#
Species.Number 2
<Definition.of.Atomic.Species
C C6.0-s2p2d1 C_PBE13
E Rn13.0-s2p2d2f1 E
Definition.of.Atomic.Species>


Atoms.Number 12
Atoms.SpeciesAndCoordinates.Unit Ang # Ang|AU
<Atoms.SpeciesAndCoordinates # Unit=Ang.
1 C 20.000000000 0.000000000 0.000000000 2.0 2.0
2 C 21.000000000 2.840000000 0.000000000 2.0 2.0
3 C 20.000000000 0.710000000 1.229756000 2.0 2.0
4 C 19.000000000 2.130000000 1.229756000 2.0 2.0
5 C 20.000000000 4.260000000 0.000000000 2.0 2.0
6 C 21.000000000 7.100000000 0.000000000 2.0 2.0
7 C 20.000000000 4.970000000 1.229756000 2.0 2.0
8 C 19.000000000 6.390000000 1.229756000 2.0 2.0
9 C 20.000000000 8.520000000 0.000000000 2.0 2.0
10 C 21.000000000 11.36000000 0.000000000 2.0 2.0
11 C 20.000000000 9.230000000 1.229756000 2.0 2.0
12 C 19.000000000 10.65000000 1.229756000 2.0 2.0
Atoms.SpeciesAndCoordinates>
Atoms.UnitVectors.Unit Ang # Ang|AU
<Atoms.UnitVectors # unit=Ang.
40.00000000000000 0.00000000000000 0.00000000000000
0.00000000000000 12.7800000000000 0.00000000000000
0.00000000000000 0.00000000000000 2.45951214674781
Atoms.UnitVectors>


# SCF or Electronic System
#
scf.XcType GGA-PBE # LDA|LSDA-CA|LSDA-PW|GGA-PBE
scf.SpinPolarization off # On|Off|NC
scf.energycutoff 300.0 # default=150 (Ry)
scf.maxIter 100 # default=40
scf.EigenvalueSolver band # DC|GDC|Cluster|Band
scf.Kgrid 1 3 11 # means n1 x n2 x n3
scf.Mixing.Type rmm-diisk # Simple|Rmm-Diis|Gr-Pulay|Kerker|Rmm-Diisk
scf.Init.Mixing.Weight 0.30 # default=0.30
scf.Min.Mixing.Weight 0.001 # default=0.001
scf.Max.Mixing.Weight 0.700 # default=0.40
scf.Mixing.History 10 # default=5
scf.Mixing.StartPulay 5 # default=6
scf.Mixing.EveryPulay 1 # default=5
scf.criterion 1.0e-6 # default=1.0e-6 (Hartree)
scf.lapack.dste dstevx # dstegr|dstedc|dstevx, default=dstevx
scf.system.charge 0.0
ESM.switch on2 # off, on1=v|v|v, on2=m|v|m, on3=v|v|m, on4=on2+EF
ESM.buffer.range 4.5 # default=10.0 (ang)


scf.restart off
scf.fixed.grid 0.00000000000000 0.00000000000000 0.00000000000000


------- Super-cell configure for C8 case -----
Atoms.Number 8
Atoms.SpeciesAndCoordinates.Unit Ang # Ang|AU
<Atoms.SpeciesAndCoordinates # Unit=Ang.
1 C 20.000000000 0.000000000 0.000000000 2.0 2.0
2 C 21.000000000 2.840000000 0.000000000 2.0 2.0
3 C 20.000000000 0.710000000 1.229756000 2.0 2.0
4 C 19.000000000 2.130000000 1.229756000 2.0 2.0
5 C 20.000000000 4.260000000 0.000000000 2.0 2.0
6 C 21.000000000 7.100000000 0.000000000 2.0 2.0
7 C 20.000000000 4.970000000 1.229756000 2.0 2.0
8 C 19.000000000 6.390000000 1.229756000 2.0 2.0
Atoms.SpeciesAndCoordinates>
Atoms.UnitVectors.Unit Ang # Ang|AU
<Atoms.UnitVectors # unit=Ang.
40.00000000000000 0.00000000000000 0.00000000000000
0.00000000000000 8.52000000000000 0.00000000000000
0.00000000000000 0.00000000000000 2.45951214674781
Atoms.UnitVectors>
------- C8 case could converge smoothly -----
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Re: The Divergence of graphene calulcation in ESM model (ON2, M|V|M) ( No.1 )
Date: 2017/03/11 09:33
Name: T. Ozaki

Hi,

I think that this must be a bug related to 'on2'.
Once the problem is fixed, the patch will be released.

Regards,

TO
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