Example: GO cyclobutadiene unpaired electrons¶

#!/bin/sh

AMS_JOBNAME=singlet $AMSBIN/ams << eor

Task GeometryOptimization

GeometryOptimization
   Convergence Gradients=1.0e-5
   CoordinateType Cartesian
End

System
    Atoms
        C         0.6  0.8  0.00000000
        C        -0.6  0.8  0.00000000
        C        -0.6 -0.8  0.00000000
        C         0.6 -0.8  0.00000000
        H         1.4  1.4  0.00000000
        H        -1.4  1.4  0.00000000
        H        -1.4 -1.4  0.00000000
        H         1.4 -1.4  0.00000000
    End
End

Engine DFTB
   Model SCC-DFTB
   ResourcesDir DFTB.org/mio-1-1
   Occupation
      Strategy aufbau
   End
   UnpairedElectrons 0
EndEngine

eor


AMS_JOBNAME=triplet $AMSBIN/ams << eor

Task GeometryOptimization

GeometryOptimization
   Convergence Gradients=1.0e-5
   CoordinateType Cartesian
End

System
    Atoms
        C         0.6  0.8  0.00000000
        C        -0.6  0.8  0.00000000
        C        -0.6 -0.8  0.00000000
        C         0.6 -0.8  0.00000000
        H         1.4  1.4  0.00000000
        H        -1.4  1.4  0.00000000
        H        -1.4 -1.4  0.00000000
        H         1.4 -1.4  0.00000000
    End
End

Engine DFTB
   Model SCC-DFTB
   ResourcesDir DFTB.org/mio-1-1
   Occupation
      Strategy aufbau
   End
   UnpairedElectrons 2
EndEngine

eor