Example: CV(n)-DFT excitation energies: Formamide¶

Download Formamide_CVnDFT.run

Calculation of the excitation energies of Formamide using the CV(n)-DFT method. Due to bugs in older versions it is important to use ADF2016.105 or later.

Example of CV(\(\infty\))-DFT where the molecular orbitals for the particular excitation are optimized (relaxed), which is called the R-CV(\(\infty\))-DFT method. In this case, the transition U-vector is frozen, while the orbitals are relaxed. ALLPOINTS should be used in case of a symmetric molecule. EXACTDENSITY should be used for precision reasons. Note that the irrep labels for C(s) symmetry that are used in the excitation code (A’ and A’‘) differ from those that are used during the SCF (AA and AAA).

$ADFBIN/adf <<eor
Title Formamide
basis
 Type DZ
 Core None
end
Numericalquality good
atoms
 H -0.927427 -0.600301 0.000000
 H  1.070498 -1.782390 0.000000
 H  2.024514 -0.325050 0.000000
 C  0.000000  0.000000 0.000000
 O  0.000000  1.225060 0.000000
 N  1.119392 -0.775069 0.000000
end
allpoints
xc
 hybrid B3LYP
end
CVnDFT
 ITERATION 10
 TOLERANCE 0.001
 R_CV_DFT &
  RELAXALPHA 1
  RELAXBETA 1
  DAMPORBRELAX 0.2
 SUBEND
END
TDA
EXACTDENSITY
EXCITATION
 Davidson &
  A' 2
  A'' 2
 SUBEND
 lowest 4
 ONLYSING
 ANALYTICAL
 TOLERANCE 1e-5
END
end input
eor