# Example: Numerical Frequencies of an excited state: PH2¶

```
#!/bin/sh
# Example for an excited state geometry optimization and frequency calculation.
# Needed for such excited state optimizations are the key EXCITATIONS (to
# calculate excitation energies), and the key EXCITEDGO (to select for which
# excitation a geometry optimization should be performed).
# The ground state and excited state are openshell.
AMS_JOBNAME=PH2 $AMSBIN/ams <<eor
System
atoms
P 0.000000 0.000000 0.0
H 0.7 0.0 0.7
H -0.7 0.0 0.7
end
end
Task GeometryOptimization
GeometryOptimization
Convergence
energy 0.0001
gradients 0.0001
End
MaxIterations 50
End
Engine ADF
title PH2 Excited state geometry
beckegrid
quality good
end
exactdensity
excitations
lowest 10
onlysing
end
excitedgo
output 1
state B2 1
end
basis
core NONE
type DZ
end
scf
converge 1.0e-9
end
unrestricted
spinpolarization 1
xc
gga BP86
end
EndEngine
eor
# Next the frequencies are calculated of the excited state. LoadSystem is used to
# pick up the optimized 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 1'. Accurate SCF convergence parameters are used.
AMS_JOBNAME=PH2_Freq $AMSBIN/ams <<eor
LoadSystem
File PH2.results/adf.rkf
End
Task SinglePoint
Properties
NormalModes Yes
End
Engine ADF
title PH2 Excited state frequencies
beckegrid
quality good
end
exactdensity
excitations
lowest 10
onlysing
end
symmetry nosym
excitedgo
cpks
eps 0.000001
end
output 2
state A 1
end
basis
type DZ
core NONE
end
scf
converge 1.0e-9
end
spinpolarization 1
unrestricted
xc
gga BP86
end
EndEngine
eor
```