#!/bin/sh

# Excited state geometry optimization using TD-DFT+TB,
# for the radical cation of Pyrazine (open shell doublet).
# The lowest unrestricted excited state is optimized.
# This method is meant for GGA or LDA functionals. In this example LDA functional PW92
# is used during the SCF. In the the calculation of the excitation energies the
# TD-DFTB+TB method is used in which the required integrals are approximated in
# the same way as in a TD-DFTB calculation. Symmetry NOSYM is required.
# For excited state gradients all electron basis sets are required.

# Note that for symmetric systems, one could perturb the coordinates
# to break the symmetry of the system. This can be done, for example,
# by including PerturbCoordinates 0.05 in the System block.
# In this example this is not done, which in practice means that the
# molecule remains symmetric.

$AMSBIN/ams <<eor
system
  Atoms
    H 0.000000 2.068464 1.258236
    H 0.000000 -2.068464 1.258236
    H 0.000000 2.068464 -1.258236
    H 0.000000 -2.068464 -1.258236
    C 0.000000 1.135920 0.697884
    C 0.000000 -1.135920 0.697884
    C 0.000000 1.135920 -0.697884
    C 0.000000 -1.135920 -0.697884
    N 0.000000 0.000000 1.417402
    N 0.000000 0.000000 -1.417402
  End
  charge 1
End

Task GeometryOptimization

GeometryOptimization
END

Engine adf
  Basis
     Type DZP
     Core none
  End
  XC
    LDA PW92
  End
  SYMMETRY NOSYM
  numericalquality good
  unrestricted Yes
  SpinPolarization 1.0
  EXCITATIONS
    TD-DFTB
    lowest 10
  END
  EXCITEDGO
    STATE A 1
  END
EndEngine
eor