[DFTB-Plus-User] relaxation problems using DFTB+

[Duncan Riley]

Hi

 

You might want to try the mio-0-1 parameter set for this type of system, I
used it before for atomic hydrogen binding in carbon systems.

 

Duncan

 

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

Dr Duncan Riley

Institute for Materials Research

Maxwell Building

University of Salford

+44 161 2953845

 

From: dftb-plus-user-bounces at dftb-plus.info
[mailto:dftb-plus-user-bounces at dftb-plus.info] On Behalf Of Yang Ming
Sent: 03 September 2009 08:03
To: dftb-plus-user at dftb-plus.info
Subject: [DFTB-Plus-User] relaxation problems using DFTB+

 

Dear All,

 

I used DFTB+ to relax a system of Hydrogen atoms absorbed on graphene.
However, I found the system still cannot converge after two weeks, although
the system has only 32 atoms with 20 Angstrom vacuum. In contrast, I used
VASP to run this system, and it converged quite well. Any comments or
suggestions are highly appreciated. 

 

The following is the input parameters for this calculation:

 

Geometry = GenFormat {

32 S

C H

01   1   2.822666667    0.000000000   11.700000000

02   1   0.705666667    1.222500000   11.700000000

03   1  -0.000000000    0.000000000   11.700000000

04   1   2.117000000    1.222500000   11.700000000

05   1   7.056666667    0.000000000   11.700000000

06   1   4.939666667    1.222500000   11.700000000

07   1   4.234000000    0.000000000   11.700000000

08   1   6.351000000    1.222500000   11.700000000

09   1  11.290666667    0.000000000   11.700000000

10   1   9.173666667    1.222500000   11.700000000

11   1   8.468000000    0.000000000   11.700000000

12   1  10.585000000    1.222500000   11.700000000

13   1  15.524666667    0.000000000   11.700000000

14   1  13.407666667    1.222500000   11.700000000

15   1  12.702000000    0.000000000   11.700000000

16   1  14.819000000    1.222500000   11.700000000

17   1  19.758666667    0.000000000   11.700000000

18   1  17.641666667    1.222500000   11.700000000

19   1  16.936000000    0.000000000   11.700000000

20   1  19.053000000    1.222500000   11.700000000

21   1  23.992666667    0.000000000   11.700000000

22   1  21.875666667    1.222500000   11.700000000

23   1  21.170000000    0.000000000   11.700000000

24   1  23.287000000    1.222500000   11.700000000

25   1  28.226666667    0.000000000   11.700000000

26   1  26.109666667    1.222500000   11.700000000

27   1  25.404000000    0.000000000   11.700000000

28   1  27.521000000    1.222500000   11.700000000

29   2  -0.000000000    0.000000000   10.560000019

30   2   4.234000000    0.000000000   10.560000019

31   2   8.468000000    0.000000000   10.560000019

32   2  12.702000000    0.000000000   10.560000019

0.00000  0.00000  0.00000

29.6380  0.00000  0.00000

0.00000  2.44500  0.00000

0.00000  0.00000  20.0000

}

Driver = ConjugateGradient {

  MovedAtoms = Range { 1 -1 }

  MaxForceComponent [eV/AA] = 1.0e-2

  MaxSteps = 100000

  OutputPrefix = "geom.out"

}

Hamiltonian = DFTB {

  SCC = Yes

  SCCTolerance = 2.0e-5

  MaxSCCIterations = 1000

  Mixer = Broyden {

    MixingParameter = 0.2

    CachedIterations = -1

    InverseJacobiWeight = 1.000000000000000E-002

    MinimalWeight = 1.00000000000000

    MaximalWeight = 100000.000000000

    WeightFactor = 1.000000000000000E-002

  }

  KPointsAndWeights = SupercellFolding {

1 0 0

0 9 0

0 0 1

0.0 0 0

  }

  SlaterKosterFiles = {

    C-C = "C-C.skf"  # pbc-0-2

    C-H = "C-H.skf"  # pbc-0-2

    H-C = "H-C.skf"  # pbc-0-2

    H-H = "H-H.skf"  # pbc-0-2

  }

MaxAngularMomentum = {

    C = "p"

    H = "s"

  }

 

  Charge = 0.0

  SpinPolarisation = {}

  Filling = Fermi {

    Temperature = 1.000000000000000E-008

    IndependentKFilling = No

  }

  ElectricField = {}

  OrbitalResolvedSCC = No

  ReadInitialCharges = No

  Eigensolver = DivideAndConquer {}

  OldSKInterpolation = No

  OrbitalPotential = {}

  Dispersion = {}

}

 

ParserOptions = {

  ParserVersion = 3

  WriteHSDInput = Yes

  WriteXMLInput = No

  StopAfterParsing = No

}

Options = {

  WriteEigenvectors = No

  WriteAutotestTag = No

  WriteDetailedXML = No

  WriteResultsTag =  Yes

  WriteDetailedOut = Yes

  WriteBandOut = Yes

  AtomResolvedEnergies = Yes

  RestartFrequency = 20

  RandomSeed = 0

}

 

 

 

Best regards,

Yang Ming

*****

Computational Condense-Matter Physics Lab

Department of Physics,

National University of Singapore, 

Singapore, 117542

Email: mingyang at nus.edu.sg

Tel (Office): +65 6516 4335

 

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