Example: ESR g-tensor, A-tensor, perturbative spin-orbit coupling: HgF¶

#!/bin/sh


# This example calculates the ESR g-tensor and A-tensor for HgF. In this example
# first spin-orbit coupling is taken into account perturbatively.

# Note that an all-electron calculation is carried out. This is relevant for the
# computation of the A-tensor, the nuclear magnetic dipole hyperfine
# interaction, where an accurate value of the spin-polarization density at the
# nucleus is important. For the g-tensor this plays a minor role. However, for
# the g-tensor calculation that includes spin-orbit coupling perturbatively, all
# electron basis sets are necessary.

# In the first example the module nmr calculates the g-tensor (subkey GFACTORS)
# using spin-orbit coupling and the external magnetic field as perturbation.


AMS_JOBNAME=HgF $AMSBIN/ams <<eor
System
  atoms
     Hg        0.0 0.0 0.0
     F         0.0 0.0 2.804
  end
end

Task SinglePoint

Engine ADF
  beckegrid
    quality verygood
  end
  basis
    core None
    type TZ2P
  end
  relativity
    level scalar
    formalism ZORA
  end
  save TAPE21 TAPE10
  scf
    converge 1e-7 1e-7
    iterations 500
  end
  spinpolarization 1
  symmetry NoSym
  unrestricted
  usespcode
  xc
    gga PBE
  end
EndEngine
eor

$AMSBIN/nmr <<eor
  tape10file HgF.results/TAPE10
  adffile HgF.results/adf.rkf
  nmr
   gfactors 
   u1k best
   out iso tens 
  end
eor

# In the second example the module cpl calculates the A-tensor (key HYPERFINE)
# using spin-orbit coupling and the nuclear magnetic field as perturbation. Note
# that one needs to set the SCF convergence criterium to a small value. For an
# accurate calculation of the A-tensor one needs a very large basis set in the
# core region (especially tight s-functions), especially for heavy nuclei. If
# one has such a large basis set in the core region, one can also see an effect
# of using a finite size of the nucleus instead of a point nucleus. Such large
# basis sets can be found for some elements in $AMSRESOURCES/ADF/ZORA/jcpl, which
# are basis sets especially designed for ESR A-tensor and NMR spin-spin coupling
# calculations.


AMS_JOBNAME=HgF_jcpl $AMSBIN/ams <<eor
System
  atoms
     Hg        0.0 0.0 0.0
     F         0.0 0.0 2.804
  end
end

Task SinglePoint

Engine ADF
  beckegrid
    quality verygood
  end
  basis
    PerAtomType Symbol=Hg File=ZORA/jcpl/Hg
    PerAtomType Symbol=F  File=ZORA/jcpl/F
  end
  nuclearmodel Gaussian
  relativity
    level scalar
    formalism ZORA
  end
  scf
    converge 1e-7 1e-7
    iterations 500
  end
  spinpolarization 1
  symmetry NoSym
  unrestricted
  usespcode
  xc
    gga PBE
  end
EndEngine
eor

$AMSBIN/cpl <<eor
  adffile HgF_jcpl.results/adf.rkf
  gga
  hyperfine
   atoms 1 2 :: calculates A-tensor for atom 1 and 2, input order
   SCF Converge=1e-7
  end
eor