[DFTB-Plus-User] band structure SCC convergence

R.Perez Garcia r.perez.garcia at student.rug.nl
Wed Jul 11 09:04:02 CEST 2012


> Dear Prof. Aradi,
> 
Dear DFTB+ especialists,

> 
> 
> 
> 
> 
> I am starting to use DBTB+ and I successfully did so until now. 
> I can not
>  calculate the band structure due to a convergence problem.
> 
> I did follow your tutorial, and after SCC convergence (21iterations) and
>  satisfactorily calculate the DOS, the BandStructure calculation 
> crashes.
> 
> 
> 
> I put the necessary files, charges.bin and geom.gen, in a new directory 
>  together with the dftb_in.hsd (with all the small changes suggested by you, I think ) but it
>  can not converged.
> 
> 
> 
> I suppose you are busy but it is a couple of days i am trying to short 
> out this problem unsuccessfully. In Morokuma's group (where i am studying 
> now) nobody can help me with the use these tools of DFTB+ and I would be very grateful if you 
> can dedicate a few minutes.
> 
> 
> 
> I need to do only a monodimensional scan over the band. the system is 
> periodic in 3D but its real periodicity can be consider as to be in only
>  one direction like nanowires in a cell with big b and c. 
> I am using the following input: 
>  Geometry = GenFormat {
>   <<< "geom.gen"
>   }
>  Driver = {}
> 
> Hamiltonian = DFTB {               # DFTB Hamiltonian
>         SCC = Yes                        
>         SCCTolerance = 1.0e-008            # Tolerance for charge consistence
>         MaxSCCIterations = 1           # Nr. of maximal SCC iterations
>         Mixer = Broyden {}
>         Eigensolver = DivideAndConquer {}
>         MaxAngularMomentum = {           # Maximal l-value of the various species
>         C = "p"
>         H = "s"
>         S = "p"
>         N = "p"
>         O = "p"
>         }
>         Charge = 0.000
>         Dispersion = LennardJones {
>         Parameters = UFFParameters {}
>         }
>         Filling = Fermi {
>         Temperature [K] = 0
>         }
>         SlaterKosterFiles =  Type2FileNames {            # Specifying Slater-Koster files
>          Prefix = '/home/morokuma4/rpg/Rodrigo/slko.5425/'
>          Separator = ""
>          Suffix = ".spl"
>          LowerCaseTypeName = Yes
>         }
>         ReadInitialCharges = Yes
>         KPointsAndWeights = Klines {
>         1 0.0 0.0 0.0 # 0.0.0
>         10 0.5 0.0 0.0  ##I also try the value of pi/a = 0.065  # is the vector of the cell i use
>         }
> }
> Options = {
>   WriteEigenvectors = No
>   WriteAutotestTag = No
>   WriteDetailedXML = No
>   WriteResultsTag = No
>   WriteDetailedOut = Yes
>   WriteBandOut = Yes
>   AtomResolvedEnergies = No
>   RandomSeed = 1
>   ShowFoldedCoords = Yes
>   RestartFrequency = 0
> }
> ParserOptions = {
>   ParserVersion = 4
>   WriteHSDInput = Yes
>   WriteXMLInput = No
>   StopAfterParsing = No
> }
> 
> 
> Thank you very much for your time.
> 
> Yours sincerely: Rodrigo
> 
> 


the output file last four lines:
 Total Mermin free energy:        -601.6907975337 H
ERROR!
-> SCC is NOT converged, maximal SCC iterations exceeded
Thu Jul 12 14:44:25 JST 2012
/home/morokuma4/rpg/Rodrigo/data/coupl500/PCBMnma_Copol1_500K/3/MD/run5/test/K4/band






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