[DFTB-Plus-User] FW: Problem in SCC convergence

Fateme Hooshmand fateme.hooshmand at lnu.se
Mon Aug 17 12:28:16 CEST 2015


________________________________________
From: Fateme Hooshmand
Sent: Monday, August 17, 2015 11:55 AM
To: DFTB-Plus-User at dftb-plus.info
Subject: Problem in SCC convergence

Dear DFTB+ Users
I did DOS calculation without any problem in SCC convergence but the Band-calculation have not got any result due to convergence problem in SCC. In my knowledge in both of this calculations have the same method for projecting wave functions but only with selected strips of k-points for band structure. So, this is the only difference between these two input files.  These are input files for DOS and Band calculations:
DOS:
Driver ={
}
Hamiltonian = DFTB {
SCC = Yes
SCCTOlerance = 1e-7
MaxSCCIterations = 2000
MaxAngularMomentum = {
C = "p";
}
SlaterKosterFiles = Type2FileNames {
C-C = "C-C.skf"
Prefix = "./SK/"
Separator = "-"
Suffix = ".skf"
}
Filling = Fermi {
Temperature [Kelvin] = 1.000000000000000E-008
}
KPointsAndWeights = SupercellFolding {
     1 0  0
     0 1  0
     0 0  11
     1 1  1
 }
}
Analysis {
  ProjectStates {
    Region {
      Atoms = C
      ShellResolved = Yes
      Label = "dos_C"
    }
#####################################################
band:
Driver ={
}
Hamiltonian = DFTB {
SCC = Yes
SCCTOlerance = 1e-7
MaxSCCIterations = 1
MaxAngularMomentum = {
C = "p";
}
SlaterKosterFiles = Type2FileNames {
C-C = "C-C.skf"
Prefix = "./SK/"
Separator = "-"
Suffix = ".skf"
}
Filling = Fermi {
Temperature [Kelvin] =  1.000000000000000E-008
}
ReadInitialCharges = Yes
KPointsAndWeights = Klines{
 1  0.0 0.0  0.0
 1  0.5 0.5 -0.5
 }
}
Options = {
WriteResultsTag = Yes
RestartFrequency = 0
}
ParserOptions {
ParserVersion = 4
IgnoreUnprocessedNodes = Yes
}
################################################
error message:
********************************************************************************
** Geometry step: 0
********************************************************************************

  iSCC Total electronic   Diff electronic      SCC error
    1   -0.13272902E+03    0.00000000E+00    0.19625336E-04

 Total Energy:                    -121.0746363928 H
 Total Mermin free energy:        -121.0746363928 H
ERROR!
-> SCC is NOT converged, maximal SCC iterations exceeded



PLEASE let me know how I can fixed this problem ?
Thank you in advance
best




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