Example: GO poly-ethyleen

Download GO_PEChain.run

#!/bin/sh


# first run: optimize coordinates with a fixed unit cell

AMS_JOBNAME=fixed $AMSBIN/ams << eor

Task GeometryOptimization

GeometryOptimization
  Convergence Gradients=0.0001
End

System
    Atoms [Bohr]
        C  -1.20630475   0.00000000   0.80181600
        C   1.20630475   0.00000000  -0.80181600
        H  -1.20630475   1.68180819   1.99106085
        H  -1.20630475  -1.68180819   1.99106085
        H   1.20630475   1.68180819  -1.99106085
        H   1.20630475  -1.68180819  -1.99106085
    End
    Lattice [Bohr]
       5.7 0 0
    End
End

Engine DFTB
   ResourcesDir Dresden
   Model DFTB0
   KSpace
       Type Symmetric
       Symmetric KInteg=5
   End
   Technical AnalyticalStressTensor=False # Not yet supported with symmetric k-space grid ...
EndEngine

eor


# second run: also optimize lattice vectors

AMS_JOBNAME=lattice $AMSBIN/ams << eor

Task GeometryOptimization

GeometryOptimization
  Convergence Gradients=0.0001
  OptimizeLattice yes
End

System
    Atoms [Bohr]
        C  -1.20630475   0.00000000   0.80181600
        C   1.20630475   0.00000000  -0.80181600
        H  -1.20630475   1.68180819   1.99106085
        H  -1.20630475  -1.68180819   1.99106085
        H   1.20630475   1.68180819  -1.99106085
        H   1.20630475  -1.68180819  -1.99106085
    End
    Lattice [Bohr]
       5.7 0 0
    End
End

Engine DFTB
   ResourcesDir Dresden
   Model DFTB0
   KSpace
       Type Symmetric
       Symmetric KInteg=5
   End
   Technical AnalyticalStressTensor=False # Not yet supported with symmetric k-space grid ...
EndEngine

eor