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DFT-D3 for graphene
Date: 2017/01/27 03:03
Name: S Dechamps   <samuel.dechamps@student.uclouvain.be>

Dear OpenMX users,

I'm currently doing some dummy calculations, in order to do LS-DFT with vdw for transport later on. I chose to study the well-known case of graphene-bilayer (GB) (the script is given hereafter). I use DFT-D3 and therefore I'd expect something larger than dz=3.35 (exp. value), as demonstrated for GB interlayer distance. Nevertheless, I get after relaxation dz=3.24 with s2p2d1,s3p3d1 and s3p3d2 ... (with MD.Opt.criterion 1.0e-5). I think that I did a mistake somewhere, so could you please help me to clear this out ?

Thanks for your help,
Best

###########################################################################################

#
# Definition of Atomic Species
#

Species.Number 1
<Definition.of.Atomic.Species
C C5.0_GGA-s3p3d1 C5.0_GGA
Definition.of.Atomic.Species>

#
# Atoms
#

Atoms.Number 4
Atoms.SpeciesAndCoordinates.Unit FRAC # Ang|AU
<Atoms.SpeciesAndCoordinates
1 C 0.00000000000000 0.00000000000000 0.000 2.0 2.0
2 C 0.33333333333333 0.33333333333333 0.000 2.0 2.0
3 C 0.33333333333333 0.33333333333333 0.108 2.0 2.0
4 C 0.66666666666666 0.66666666666666 0.108 2.0 2.0
Atoms.SpeciesAndCoordinates>

Atoms.UnitVectors.Unit Ang # Ang|AU
<Atoms.UnitVectors
0.639541860448 2.386802716760 0.000000000
2.386802716760 0.639541860448 0.000000000
0.000000000000 0.000000000000 30.000000000
Atoms.UnitVectors>

#The unit cell is oriented 45° wrt x and y to minimize pao orientation effects when
#computing the forces

#
# SCF or Electronic System
#

scf.XcType GGA-PBE # LDA|LSDA-CA|LSDA-PW|GGA-PBE
scf.SpinPolarization off # On|Off|NC
scf.SpinOrbit.Coupling off
scf.ElectronicTemperature 300.0 # default=300 (K)
scf.energycutoff 900.0 # default=150 (Ry)
scf.maxIter 200 # default=40
scf.EigenvalueSolver Band # DC|GDC|Cluster|Band
scf.Kgrid 36 36 1 # 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 0.400 # default=0.40
scf.Mixing.History 50 # default=5
scf.Mixing.StartPulay 5 # default=6
scf.criterion 1.0e-9 # default=1.0e-6 (Hartree)
scf.lapack.dste dstevx # dstevx|dstedc|dstegr,default=dstevx
scf.restart off

#
# MD or Geometry Optimization
#

MD.Type BFGS # Nomd|Opt|DIIS|NVE|NVT_VS|NVT_NH
MD.Opt.DIIS.History 7 # default=7
MD.Opt.StartDIIS 5 # default=5
MD.Opt.EveryDIIS 200 # default=200
MD.maxIter 200 # default=1
MD.Opt.criterion 1.0e-5 # default=1.0e-4 (Hartree/bohr)

<MD.Fixed.XYZ
1 1 1 0
2 1 1 0
3 1 1 0
4 1 1 0
MD.Fixed.XYZ>

#
# vdW
#

scf.dftD on
version.dftD 3
DFTD3.damp zero
DFTD.IntDirection 1 1 0

###########################################################################################
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Re: DFT-D3 for graphene ( No.1 )
Date: 2017/03/02 14:51
Name: T. Ozaki

Hi,

I also repeated similar calculations with attached input, and
obtained the following results for the interlayer distance between
two graphene sheets:

3.48 Ang. in case of DFTD3.damp zero
3.38 Ang. in case of DFTD3.damp bj

The case with 'bj' is well compared with other computational results.

I guess that the cutoff radius of basis functions and DFTD3.damp
affect the interlayer distance.

Regards,

TO

---------------------------------------------------------

#
# File Name
#

System.CurrrentDirectory ./ # default=./
System.Name bg1
level.of.stdout 1 # default=1 (1-3)
level.of.fileout 1 # default=1 (0-2)

#
# Definition of Atomic Species
#

Species.Number 1
<Definition.of.Atomic.Species
C C7.0-s2p2d1 C_PBE13
Definition.of.Atomic.Species>

#
# Atoms
#

Atoms.Number 4
Atoms.SpeciesAndCoordinates.Unit FRAC # Ang|AU
<Atoms.SpeciesAndCoordinates
1 C 0.00000000000000 0.00000000000000 0.000 2.0 2.0
2 C 0.33333333333333 0.33333333333333 0.000 2.0 2.0
3 C 0.33333333333333 0.33333333333333 0.108 2.0 2.0
4 C 0.66666666666666 0.66666666666666 0.108 2.0 2.0
Atoms.SpeciesAndCoordinates>

Atoms.UnitVectors.Unit Ang # Ang|AU
<Atoms.UnitVectors
0.639541860448 2.386802716760 0.000000000
2.386802716760 0.639541860448 0.000000000
0.000000000000 0.000000000000 30.000000000
Atoms.UnitVectors>

#The unit cell is oriented 45° wrt x and y to minimize pao orientation effects when
#computing the forces

#
# SCF or Electronic System
#

scf.XcType GGA-PBE # LDA|LSDA-CA|LSDA-PW|GGA-PBE
scf.SpinPolarization off # On|Off|NC
scf.SpinOrbit.Coupling off
scf.ElectronicTemperature 300.0 # default=300 (K)
scf.energycutoff 900.0 # default=150 (Ry)
scf.maxIter 200 # default=40
scf.EigenvalueSolver Band # DC|GDC|Cluster|Band
scf.Kgrid 21 21 1 # 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 0.400 # default=0.40
scf.Mixing.History 50 # default=5
scf.Mixing.StartPulay 5 # default=6
scf.criterion 1.0e-9 # default=1.0e-6 (Hartree)
scf.lapack.dste dstevx # dstevx|dstedc|dstegr,default=dstevx
scf.restart off

#
# MD or Geometry Optimization
#

MD.Type BFGS # Nomd|Opt|DIIS|NVE|NVT_VS|NVT_NH
MD.Opt.DIIS.History 7 # default=7
MD.Opt.StartDIIS 5 # default=5
MD.Opt.EveryDIIS 200 # default=200
MD.maxIter 200 # default=1
MD.Opt.criterion 1.0e-5 # default=1.0e-4 (Hartree/bohr)

<MD.Fixed.XYZ
1 1 1 0
2 1 1 0
3 1 1 0
4 1 1 0
MD.Fixed.XYZ>

#
# vdW
#

scf.dftD on
version.dftD 3
DFTD3.damp bj
DFTD.IntDirection 1 1 0

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