Example: Vibronic-Structure Tracking¶

#!/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