Example: Mössbauer with X2C: Hg compounds¶

#! /bin/sh


# This example uses the relativistic spin-orbit coupled X2C method. By default
# in ADF the electron density at the nuclei is calculated, no input key is
# required. The electron density at the nuclei could be used for the
# interpretation of isomer shifts in Mossbauer spectroscopy. Typically one needs
# to perform a fit of the experimentally measured isomer shifts versus the
# calculated electron densities. The absolute electron density at a nucleus
# heavily depends on the accuracy of the basis set in the core region of this
# nucleus, especially if relativistic effects are included. Important is to use
# the same basis set, same exchange correlation functional, same numerical
# accuracy, if electron densities at nuclei in different molecules are compared.
# For the calculation of Mossbauer qadrupole splittings the key QTENS is
# required This example calculates the compounds Hg, HgF, HgF2, HgF4, and HgCl2.


AMS_JOBNAME=Hg_X2C $AMSBIN/ams <<eor
System
  atoms
     Hg 0 0 0
  end
end

Task SinglePoint

Engine ADF
  exactdensity
  basis
    core None
    type ZORA/DZ
  end
  nuclearmodel gaussian
  numericalquality good
  relativity
    level spin-orbit
    formalism X2C
  end
EndEngine
eor


AMS_JOBNAME=HgF_X2C $AMSBIN/ams <<eor
System
  atoms
     Hg 0 0 0
     F  0 0 2.007
  end
end

Task SinglePoint

Engine ADF
  exactdensity
  basis
    core None
    type ZORA/DZ
  end
  nuclearmodel gaussian
  numericalquality good
  qtens
  relativity
    Level spin-orbit
    Formalism X2C
    SpinOrbitMagnetization NonCollinear
  end
  symmetry nosym
  unrestricted
EndEngine
eor


AMS_JOBNAME=HgF2_X2C $AMSBIN/ams <<eor
System
  atoms
     Hg 0 0  0
     F  0 0  1.914
     F  0 0 -1.914
  end
end

Task SinglePoint

Engine ADF
  exactdensity
  basis
    core None
    type ZORA/DZ
  end
  nuclearmodel gaussian
  numericalquality good
  qtens
  relativity
    level spin-orbit
    formalism X2C
  end
EndEngine
eor


AMS_JOBNAME=HgF4_X2C $AMSBIN/ams <<eor
System
  atoms
     Hg  0     0     0
     F   0    -1.885 0
     F   0     1.885 0
     F  -1.885 0     0
     F   1.885 0     0
  end
end

Task SinglePoint

Engine ADF
  exactdensity
  basis
    core None
    type ZORA/DZ
  end
  nuclearmodel gaussian
  numericalquality good
  qtens
  relativity
    level spin-orbit
    formalism X2C
  end
EndEngine
eor


AMS_JOBNAME=HgCl2_X2C $AMSBIN/ams <<eor
System
  atoms
     Hg 0 0  0
     Cl 0 0  2.252
     Cl 0 0 -2.252
  end
end

Task SinglePoint

Engine ADF
  exactdensity
  basis
    core None
    type ZORA/DZ
  end
  nuclearmodel gaussian
  numericalquality good
  qtens
  relativity
    level spin-orbit
    formalism X2C
  end
EndEngine
eor