Example: TDDFT-aas: Singlet excited state geometry optimization¶

#! /bin/sh

# Excited state geometry optimization using TDDFT-aas, for the molecule Furan.
# The lowest singlet excited state S1 is optimized.
# This method is meant for GGA or LDA functionals, 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
      C      -0.3794795800       0.6253630100       0.0000000000
      C       0.8347990000      -0.1408004800       0.0000000000
      C      -1.4034209400      -0.2770148700       0.0000000000
      O      -0.9123264600      -1.5648407100       0.0000000000
      C       0.4613593600      -1.4534489500       0.0000000000
      H      -0.4753888200       1.7069426000       0.0000000000
      H       1.8524186400       0.2382823200       0.0000000000
      H      -2.4837942800      -0.1874789500       0.0000000000
      H       1.0075920800      -2.3897179700       0.0000000000
  end
end

Task GeometryOptimization

Engine ADF
  excitations
    onlysing
    LOWEST 10
    AAS
  end
  symmetry NOSYM
  EXCITEDGO
    State A 1
  End
  Basis
    type TZP
  core None
  End
  xc
    gga PBE
  end
EndEngine
eor