Example: Vibronic-Structure Tracking
************************************

"Download VST_pyrene.run"

   #!/bin/sh

   # This example demonstrates the usage of vibronic-structure tracking
   # on the pyrene molecule. Excited state calculations are performed within AMS and
   # at the DFTB level

   # 1. Ground state optimization with DFTB
   #---------------------------------------

   AMS_JOBNAME=GroundState $AMSBIN/ams << eor

   System
       Atoms
           C      -0.01654981       1.36506537       0.00802668
           C       0.00281590      -0.06808050       0.00051978
           C       1.19835953       2.08859192       0.00127327
           C      -1.25056871       2.05539572       0.02157814
           C       1.23682878      -0.75840671      -0.01375673
           C      -1.21209870      -0.79160461       0.00671225
           C       2.44308841       1.35898462      -0.01256813
           C       1.16450680       3.48665407       0.00772934
           C      -2.47512291       1.29231475       0.02824995
           C      -1.25452039       3.45386389       0.02759561
           C       2.46138768       0.00467142      -0.01984509
           C       1.24076149      -2.15686407      -0.02209661
           C      -2.45682219      -0.06199957       0.02121310
           C      -1.17826305      -2.18965609      -0.00177638
           C      -0.05432386       4.15935390       0.02049748
           C       0.04055488      -2.86234799      -0.01620562
           H       3.36596464       1.93801392      -0.01731234
           H       2.09583666       4.04986513       0.00239299
           H      -3.41330596       1.84611463       0.03902307
           H      -2.20073438       3.99162601       0.03767421
           H       3.39957176      -0.54912830      -0.03053168
           H       2.18696724      -2.69462025      -0.03320657
           H      -3.37969722      -0.64102946       0.02611688
           H      -2.10959908      -2.75286422       0.00274662
           H      -0.06904859       5.24837501       0.02503968
           H       0.05526108      -3.95135857      -0.02284989
       End
   End

   Task GeometryOptimization

   Engine DFTB
       Model DFTB3
       ResourcesDir DFTB.org/3ob-freq-1-2
   EndEngine

   eor

   # 2. Get lowest singlet-singlet excitation of pyrene and
   # compute the excited state gradient at the optimized GS geometry
   #----------------------------------------------------------------

   AMS_JOBNAME=ExcitedState $AMSBIN/ams << eor

   Task SinglePoint
   LoadSystem
      File ./GroundState.results/dftb.rkf
   End

   Properties
       Gradients yes
   End

   Engine DFTB
       Model DFTB3
       ResourcesDir DFTB.org/3ob-freq-1-2
       Properties
           Excitations
               TDDFTB
                   Calc Singlet
                   Lowest 1
               End
               TDDFTBGradients
                   Excitation 1
               End
           End
       End
   EndEngine

   eor

   # 3. Vibronic-structure tracking for this excitation
   # --------------------------------------------------

   AMS_JOBNAME=VibronicStructure $AMSBIN/ams << eor

   LoadSystem
      File ./GroundState.results/dftb.rkf
   End

   Task VibrationalAnalysis

   VibrationalAnalysis
      Type VibronicStructureTracking
      ExcitationSettings
         ExcitationInputFormat File
         ExcitationFile ./ExcitedState.results/dftb.rkf
         Singlet
           A 1
         End
      End
      AbsorptionSpectrum
         AbsorptionRange -500.0 4000.0
         LineWidth 100
         FrequencyGridPoints 181
      End
   End

   Engine DFTB
       Model DFTB3
       ResourcesDir DFTB.org/3ob-freq-1-2
   EndEngine

   eor

   # 4. Restart the VST run from the previous one
   # We have changed our mind and we want
   # the peaks to be a little sharper
   # ---------------------------------------------------------

   AMS_JOBNAME=VibronicStructureRestart $AMSBIN/ams << eor

   LoadSystem
      File ./GroundState.results/dftb.rkf
   End

   Task VibrationalAnalysis

   VibrationalAnalysis
      Type VibronicStructureTracking
      ExcitationSettings
         ExcitationInputFormat File
         ExcitationFile ./ExcitedState.results/dftb.rkf
         Singlet
           A 1
         End
      End
      VSTRestartFile ./VibronicStructure.results/ams.rkf
      AbsorptionSpectrum
         AbsorptionRange -500.0 4000.0
         LineWidth 50
         FrequencyGridPoints 181
      End
   End

   Engine DFTB
       Model DFTB3
       ResourcesDir DFTB.org/3ob-freq-1-2
   EndEngine

   eor
