[DFTB-Plus-User] Problem with MD calculations with Nose Hoover thermostat

[Susmita Basak]

Dear DFTB+ community Members,

I am a new user of DFTB+. I have tried to do MD calculations for 
Silicon using Nose Hoover chain thermostat. I am getting the following 
error-- 'Failure in diagonalisation routine zhegvd, non-positive 
definite overlap! Minor      1 responsible.' This error was mentioned 
couple of years ago in the mailing list but the solution to the problem 
is not available in the forum. I am copying the input files and md.out 
below. I have used the latest Slater-Koster files for Silicon which 
include d orbitals. Can you please help me with this problem ?

With best regards,
Susmita

Fritz Haber Institute of the Max Planck Society

=========================
##dftb_in.hsd

Geometry = GenFormat {
<<< "input_geometry.gen"
}

Driver = VelocityVerlet{
MovedAtoms = 1:-1
Steps = 100
TimeStep [Femtosecond] = 1 # 1 femtosecond = 1e-15 second
OutputPrefix= "geo_end"
MDRestartFrequency= 1
  Thermostat = NoseHoover{
Temperature [Kelvin] = 300.0
  CouplingStrength= 500
}
ConvergentForcesOnly = Yes
}

Hamiltonian = DFTB {
   SCC = Yes
   SCCTolerance = 1e-5
   SlaterKosterFiles = Type2FileNames {
     Prefix = 
"/mnt/lxfs1/home/basak/dftb/dftb+_1.2.2_autotest/slako/matsci-0-3/"
     Separator = "-"
     Suffix = ".skf"
   }

   MaxAngularMomentum {
     Si  = "d"
   }
   Charge = 0.0
   SpinPolarisation = {}
   Filling = Fermi {
     Temperature [Kelvin] = 300.0
   }
     KPointsAndWeights = SupercellFolding {
     8 0 0
     0 8 0
     0 0 8
     0.5 0.5 0.5
   }
}

Options = {}

ParserOptions {
   ParserVersion = 4
}

============================================
## Input Geometry

2 S  #number of atoms, geometry type supercell in Cartesian 
co-ordinates
Si
#  Index Type  Coordinates
     1     1     0.00            0.00         0.000
     2     1     1.3565168814 1.3565168814 1.3565168814
0.000000 0.000000 0.000000 # coordinate origin in Å
# Lattice vectors
  0              2.71303376291 2.71303376291
2.71303376291   0             2.71303376291
2.71303376291   2.71303376291   0

====================================================
## 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:                          -0.117899E-02 au    -0.346870E+11 
Pa
  Potential Energy:                  -2.7420859013 H          -74.6160 
eV
  MD Kinetic Energy:                  0.0014250669 H            0.0388 
eV
  Total MD Energy:                   -2.7406608344 H          -74.5772 
eV
  MD Temperature:                     0.0009500446 au         300.0000 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:                  -2.7420803400 H          -74.6158 
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