Example: Spin-flip excited state geometry optimization: CH2¶

#!/bin/sh

# Example for a spin-flip excited state geometry optimization with a triplet
# reference, and a frequency calculation afterwards.

# Needed for such excited state optimizations are the key EXCITATIONS (to
# calculate excitation energies), the key GEOMETRY (to do a geometry
# optimization) and the key EXCITEDGO (to select for which excitation a geometry
# optimization should be performed). In this case spin-flip excitations are
# calculated.


$ADFBIN/adf <<eor
TITLE CH2 Excited state geometry with triplet reference and spin-flip excitation

atoms
    C          0.000000    0.000000   0.0
    H          0.7         0.0        0.7
    H         -0.7         0.0        0.7
end

XC
END

UNRESTRICTED

CHARGE 0 2

GEOMETRY
 ITERATIONS 50
 CONVERGE E=0.0001 grad=0.00001
END

SCF
 Converge 1.0e-9
END

basis
 TYPE DZP
CORE NONE
end

excitations
LOWEST 10
end

TDA
SFTDDFT
FORCEALDA

EXCITEDGO
 STATE  B2 1
 OUTPUT 2
end

SYMMETRY C(2V)
eor

cp TAPE21 CH2.t21


# Next the frequencies are calculated of the excited state. A restart is used to
# pick up the excited state geometry of the previous calculation. Note that in a
# numerical FREQUENCIES calculation symmetry is turned off except to reduce the
# number of points calculated. Thus irrespective of the specified point group
# symmetry the symmetry label A of SYMMETRY NOSYM should be used to select the
# excited state. Care should be taken to ensure that the correct state is chosen
# in this frequencies calculation as the excited state number can change when
# the point group is changed. In this case instead of 'B2 1' one needs to select
# 'A 2'.



$ADFBIN/adf <<eor
TITLE CH2 Excited state frequencies with triplet reference and spin-flip excitation

atoms
    C          0.000000    0.000000   0.0
    H          0.7         0.0        0.7
    H         -0.7         0.0        0.7
end

RESTART 
   File CH2.t21
End

XC
END

UNRESTRICTED

CHARGE 0 2

GEOMETRY
 FREQUENCIES
 End
END

SCF
 Converge 1.0e-9
END

basis
 TYPE DZP
CORE NONE
end

excitations
LOWEST 10
end

TDA
SFTDDFT
FORCEALDA

EXCITEDGO
 STATE  A 2
 OUTPUT 2
end
SYMMETRY C(2V)
eor