Example: sTDA excitation energies: Adenine¶
Calculation of the excitation energies of Adenine using the simplified Tamm-Dancoff (sTDA) method by Grimme. This method is meant for hybrid functionals or range-separated functionals during the SCF. In this example the hybrid PBE0 is used during the SCF. In the the calculation of the excitation energies the sTDA method is used in which the required integrals are approximated. For hybrid functionals ADF will automatically set the parameters that are needed in this method. For range-separated functional one needs to set the parameters manually. Symmetry NOSYM is required. A TZP or TZ2P basis set is recommended for this method.
$ADFBIN/adf << eor
Atoms
1.N 1.966533 -0.556678 0.000000
2.C 1.351210 -1.750556 0.000000
3.N 0.039008 -2.019043 0.000000
4.C -0.679938 -0.889685 0.000000
5.C -0.192782 0.421840 0.000000
6.C 1.210298 0.557343 0.000000
7.N -2.051805 -0.746568 0.000000
8.C -2.311388 0.608600 0.000000
9.N -1.225604 1.347025 0.000000
10.N 1.828584 1.760602 0.000000
11.H 2.012099 -2.612788 0.000000
12.H -2.725918 -1.499744 0.000000
13.H -3.323166 0.988113 0.000000
14.H 1.288936 2.610953 0.000000
15.H 2.835883 1.795025 0.000000
End
Basis
type DZ
End
symmetry nosym
excitations
stda
onlysing
end
xc
hybrid pbe0
end
End Input
eor