[DFTB-Plus-User] fail to use Nose-Hoove Thermostat

[孟丽娟]

Dear All: 
    I am a new user of DFTB+. I  use  the Nose-Hoove  Thermostat to control the system temperature. However, the error " Failure in diagonalisation routine dsygvd, non-positive definite overlap! Minor      1 responsible."  is present in the log file. The structure has been  optimized and computation is normal if other thermostat way is applied, which means that the structure used is reasonable. I present the input file and corresponding md.out file  in the below section. I am looking forward to your help. 


Lijuan Meng
Southeast University



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Geometry = GenFormat {
 <<< "am-opt.gen"
 }
Driver = VelocityVerlet{
  MovedAtoms = 1:132
  Steps = 200000                   
  TimeStep [Femtosecond] = 0.5      
  OutputPrefix = "am-2500k"
  Thermostat = NoseHoover {
  Temperature [Kelvin] = 2500.0
  CouplingStrength = 500.0
 }
 # Velocities  = {
 #<<< "VELOC.DAT"
 #}
MDRestartFrequency = 1
}
Hamiltonian = DFTB {
  SCC = Yes
  SCCTolerance = 1.0e-4
  MaxSCCIterations = 200
  Mixer = Broyden {}
  Eigensolver = DivideAndConquer {}
  MaxAngularMomentum = {
    C = p
    Ni = d
  }
  Charge = 0.000
  Filling = Fermi {
    Temperature [Kelvin] = 10000
  }
  SlaterKosterFiles = {
    C-C = "C-C.skf"
    C-Ni = "C-Ni.skf"
    Ni-C = "Ni-C.skf"  
    Ni-Ni = "Ni-Ni.skf"
  }
   KPointsAndWeights = SupercellFolding{
     1 0 0
     0 1 0
     0 0 1
     0.0 0.0 0.0
  }
}
Options = { 
RandomSeed = 0
WriteDetailedOut = No
WriteBandOut = No
}
ParserOptions = {
  ParserVersion = 4
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

md.out
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 MD step:           0
 Nose-Hoover chain variables
 x:
    0.1000000000E+01    0.1000000000E+01    0.1000000000E+01
 v:
    0.0000000000E+00    0.0000000000E+00    0.0000000000E+00
 g:
    0.0000000000E+00    0.0000000000E+00    0.0000000000E+00
 Pressure:                          -0.102769E-04 au    -0.302358E+09 Pa
 Potential Energy:                -229.3775402846 H        -6241.6804 eV
 MD Kinetic Energy:                  1.5556980384 H           42.3327 eV
 Total MD Energy:                 -227.8218422463 H        -6199.3477 eV
 MD Temperature:                     0.0079170384 au        2500.0000 K
 MD step:           1
 Nose-Hoover chain variables
 x:
                 NaN                 NaN                 NaN
 v:
                 NaN                 NaN                 NaN
 g:
                 NaN                 NaN                 NaN
 Pressure:                                    NaN au              NaN Pa
 Potential Energy:                -229.3640994512 H        -6241.3147 eV
 MD Kinetic Energy:                           NaN H               NaN eV
 Total MD Energy:                             NaN H               NaN eV
 MD Temperature:                              NaN au              NaN K
 MD step:           2
 Nose-Hoover chain variables
 x:
                 NaN                 NaN                 NaN
 v:
                 NaN                 NaN                 NaN
 g:
                 NaN                 NaN                 NaN
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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