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

#!/bin/sh


# 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(infinity)-DFT where the molecular orbitals for the particular
# excitation are optimized (relaxed), which is called the R-CV(infinity)-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). The example contains of
# 2 parts. In the first example singlet-singlet excitations are calculated using
# the subkeyword ONLYSING in the EXCITATIONS block key. In the second example
# singlet-triplet excitations are calculated replacing the subkeyword ONLYSING
# with the subkeyword ONLYTRIP in the EXCITATIONS block key.


AMS_JOBNAME=SS $AMSBIN/ams <<eor
System
  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
end

Task SinglePoint

Engine ADF
  allpoints
  cvndft
    iteration 10
    r_cv_dft &
      damporbrelax 0.2
      relaxalpha 1
      relaxbeta 1
    end
    tolerance 0.001
  end
  exactdensity
  excitations
    analytical
    davidson
       A' 2
       A'' 2
    end
    lowest 4
    onlysing
    tolerance 1e-5
  end
  basis
    core None
    fittype ZORA/QZ4P
    type DZ
  end
  numericalquality good
  tda
  title Formamide
  xc
    hybrid B3LYP
  end
EndEngine
eor



AMS_JOBNAME=ST $AMSBIN/ams <<eor
System
  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
end

Task SinglePoint

Engine ADF
  allpoints
  cvndft
    iteration 10
    r_cv_dft &
      damporbrelax 0.2
      relaxalpha 1
      relaxbeta 1
    end
    tolerance 0.001
  end
  exactdensity
  excitations
    analytical
    davidson
       A' 2
       A'' 2
    end
    lowest 4
    onlytrip
    tolerance 1e-5
  end
  basis
    core None
    fittype ZORA/QZ4P
    type DZ
  end
  numericalquality good
  tda
  title Formamide
  xc
    hybrid B3LYP
  end
EndEngine
eor