[DFTB-Plus-User] MD output looks the same as all the steps with NPT ensemble

[Faruq, Muhammad]

Dear All 
Could you please help me to find out the problem from my MD calculations. It looks to me the first step  and the last step all are the same volume as well as energy. In this calculation,  I used NPT ensemble so that volume should be changed at each  step.  Here is the output and input details. Any help will be appreciated and thanks in advance 

Kind Regards
Muhammad Faruq
University of Bolton
 
MD step:           0
Volume:                             0.130165E+05 au^3
 Pressure:                           0.166809E-02 au     0.490769E+11 Pa
 Potential Energy:                -326.3118416085 H        -8879.3970 eV
 MD Kinetic Energy:                  0.0000024000 H            0.0001 eV
 Total MD Energy:                 -326.3118392085 H        -8879.3969 eV
 MD Temperature:                     0.0000000100 au           0.0032 K

MD step:        1410
 Nose-Hoover chain variables
 x:
    0.1000000000E+01    0.1000000000E+01    0.1000000000E+01
 v:
   -0.7044897072E-08   -0.7046621982E-08   -0.7046621982E-08
 g:
   -0.9999981342E+04   -0.1000000000E+05   -0.1000000000E+05
Lattice vectors (A)
  1.244800000000E+01  0.000000000000E+00  0.000000000000E+00
  0.000000000000E+00  1.244800000000E+01  0.000000000000E+00
  0.000000000000E+00  0.000000000000E+00  1.244800000000E+01
 Volume:                             0.130165E+05 au^3
 Pressure:                           0.166810E-02 au     0.490772E+11 Pa
 Potential Energy:                -326.3118436796 H        -8879.3970 eV
 MD Kinetic Energy:                  0.0000024000 H            0.0001 eV
 Total MD Energy:                 -326.3118412796 H        -8879.3970 eV
 MD Temperature:                     0.0000000100 au           0.0032 K

MD step:        5080
 Nose-Hoover chain variables
 x:
    0.1000000000E+01    0.1000000000E+01    0.1000000000E+01
 v:
   -0.2539484575E-07   -0.2539662198E-07   -0.2539662198E-07
 g:
   -0.9999894883E+04   -0.1000000000E+05   -0.1000000000E+05
Lattice vectors (A)
  1.244800000000E+01  0.000000000000E+00  0.000000000000E+00
  0.000000000000E+00  1.244800000000E+01  0.000000000000E+00
  0.000000000000E+00  0.000000000000E+00  1.244800000000E+01
 Volume:                             0.130165E+05 au^3
 Pressure:                           0.166810E-02 au     0.490772E+11 Pa
 Potential Energy:                -326.3118436796 H        -8879.3970 eV
 MD Kinetic Energy:                  0.0000024000 H            0.0001 eV
 Total MD Energy:                 -326.3118412796 H        -8879.3970 eV
 MD Temperature:                     0.0000000100 au           0.0032 K

Here is Input file: 

Geometry = GenFormat {
<<< Cu5Si.gen
}

Driver = VelocityVerlet {
  MovedAtoms =  "1:-1"
 # Steps = 250
  TimeStep = 1.0e-15                #Time interval between two MD steps
  KeepStationary = No               #Remove translational motion from the system
  MDRestartFrequency=10
  Velocities = {}
  ConvergentForcesOnly = No

  Barostat = {
    Pressure = 0
    Timescale =10
  }

  Thermostat = NoseHoover{
    Temperature [Kelvin] = TemperatureProfile { # Temperatures in K
      constant 1    0.0 # Setting T=10 K for the 0th MD-step
      linear   250 300.0 # Linearly rising T in  250 steps up to T=300 K
      linear   1415 2000.0 # Linearly rising T in  1415 steps up to T=2000 K by rate 1.2K/fs
      constant 2000 2000.0 # Constant T through 2000 steps
      exponential 1415 300.0 # Exponential decreasing in 1415 steps to T=300K
    }
    CouplingStrength=100
   IntegratorSteps = 1
  }
  OutputPrefix = "final_geo"
}

Hamiltonian = DFTB {
  SCC = Yes
SCCTolerance = 1.0e-5
  EwaldParameter = 0.1
  MaxSCCIterations = 10
  Mixer = Broyden {
    MixingParameter = 0.2
}

  MaxAngularMomentum = {
    Cu = "d"
    Si = "d"
  }

  Filling = Fermi {} 
  SlaterKosterFiles = Type2FileNames {
    Prefix = "/home/maf2mpo/FAST_cal_Others/DFTB+/sk/matsci-0-3/"
    Separator = "-"
    Suffix = ".skf"
  }

  KPointsAndWeights = {
    0.0  0.0  0.0  1.0
  }
ReadInitialCharges = Yes
}
Options = {
  WriteEigenvectors = No
  WriteResultsTag = Yes
  WriteDetailedOut = Yes
  WriteBandOut = Yes
  }