Example: FDE energy: unrestricted fragments: Ne-H2O¶

#! /bin/sh

# This is example for a calculation of FDE interaction energies in ADF for an
# open-shell frozen fragment.

# It performs single point runs for H2O and Ne, the latter unrestricted
# with LDA/DZ (all-electron) and uses these fragments in an FDE energy
# embedding calculation in which the energy of water in presence of a frozen
# (open-shell) neon atom is computed
# This is a bit of an artificial test but it serves its purpose
#
# No freeze-thaw is done, this is at present not possible with unrestricted
# (open shell) fragments, but has to be done manually, see the example in 
# $AMSHOME/examples/Test/FDE_Spin.run
#
# NumericalQuality is good which should give total energies for the
# fragments accurate at least up to 10**(-4) atomic units
#
# This test has been checked to yield the same energy as a run with a closed-
# shell (restricted) Ne atom (just comment UNRESTRICTED in the input below)
#

# Ne LDA/DZ (unrestricted)

AMS_JOBNAME=Ne $AMSBIN/ams <<eor
System
  atoms
     Ne      -1.51248       -0.03714       -0.00081
  end
end

Task SinglePoint

Engine ADF
  eprint
    scf NOPOP
    sfo NOEIG NOOVL NOORBPOP
  end
  exactdensity
  basis
    core None
    type DZ
  end
  noprint BAS FUNCTIONS
  nosymfit
  numericalquality Good
  scf
    converge 1.0e-06 1.0e-06
    iterations 100
  end
  spinpolarization 0
  symmetrytolerance 1e-2
  title Ne LDA/DZ single point, unrestricted
  unrestricted
  xc
    lda
  end
  Relativity Level=None
EndEngine
eor

mv Ne.results/adf.rkf t21.ne


# H2O LDA/DZ


AMS_JOBNAME=H2O $AMSBIN/ams <<eor
System
  atoms
     O        1.45838        0.10183        0.00276
     H        0.48989       -0.04206        0.00012
     H        1.84938       -0.78409       -0.00279
  end
end

Task SinglePoint

Engine ADF
  eprint
    scf NOPOP
    sfo NOEIG NOOVL NOORBPOP
  end
  exactdensity
  basis
    core None
    type DZ
  end
  noprint BAS FUNCTIONS
  nosymfit
  numericalquality Good
  spinpolarization 0
  symmetrytolerance 1e-2
  title H2O LDA/DZ single point
  xc
    lda
  end
  Relativity Level=None
EndEngine
eor
mv H2O.results/adf.rkf t21.water


# NH3-H2O: FDE energy of H2O in presence of frozen (unrestricted) Ne


AMS_JOBNAME=FDE $AMSBIN/ams <<eor
System
  atoms
     O        1.45838        0.10183        0.00276    adf.f=frag1
     H        0.48989       -0.04206        0.00012    adf.f=frag1
     H        1.84938       -0.78409       -0.00279    adf.f=frag1
     Ne      -1.51248       -0.03714       -0.00081    adf.f=frag2
  end
end

Task SinglePoint

Engine ADF
  eprint
    scf NOPOP
    sfo NOEIG NOOVL NOORBPOP
  end
  exactdensity
  fde
    energy
    fullgrid
    thomasfermi
  end
  fragments
     frag1  t21.water
     frag2  t21.ne type=FDE
  end
  noprint BAS FUNCTIONS
  numericalquality Good
  spinpolarization 0
  symmetrytolerance 1e-2
  title Ne-H2O LDA/Thomas-Fermi/DZ FDE single point with interaction energy
  xc
    lda
  end
  Relativity Level=None
EndEngine
eor