#!/bin/sh


# The ESR parameters of VO are calculated with the collinear approximation for
# unrestricted Spin-Orbit coupled calculations. In this example the VO-molecule
# has three unpaired electrons.

# You calculate Electron Spin Resonance properties with the keywords ESR and
# QTENS. ESR is a block-type key and is used to compute the G-tensor or the
# Nuclear Magnetic Dipole Hyperfine interaction. QTENS is a simple key and
# invokes the computation of the Nuclear Electric Quadrupole Hyperfine
# interaction.

# Proper usage of the key ESR requires that you do one of the following:

# A Spin-Orbit calculation, spin-restricted, with exactly one unpaired electron,
# or (b) A Spin-Orbit calculation, spin-unrestricted in the collinear
# approximation, or (c) No Spin-Orbit terms and spin-unrestricted. In case (a)
# and (b) you obtain the G-tensor. In case (b) and (c) you get the Magnetic
# Dipole Hyperfine interaction.

# Note: in case (a) the program also prints a Magnetic Dipole Hyperfine
# interaction data, but these have then been computed without the terms from the
# spin-density at the nucleus. Note: in case (b) and (c) one can have more than
# one unpaired electron. Note: in case (b) one has to use symmetry NOSYM.

# Two calculations are performed:

# Scalar relativistic spin-unrestricted (case c) 
# Spin-Orbit relativistic spin-unrestricted collinear (case b) 

# We first calculate the Dipole Hyperfine interaction: 
# a spin- unrestricted calculation without Spin-Orbit coupling.

# Note that one has to use ALLPOINTS in the calculation for a linear molecule to
# get results for the nuclear magnetic dipole hyperfine interaction. For an
# accurate calculation of the hyperfine interaction the numerical quality is set
# to VeryGood.

AMS_JOBNAME=scalar $AMSBIN/ams <<eor
System
  atoms
     V 0 0 0
     O 0 0 1.589
  End
End

Task SinglePoint

Engine ADF
  AllPoints
  
  ESR
  End
  
  QTens

  ZFS

  basis
    core None
    type TZ2P
  End
  
  numericalquality verygood
  
  relativity
    level scalar
    formalism ZORA
  end
  
  Unrestricted
  SpinPolarization 3
  XC
    GGA Becke Perdew
  End
EndEngine

eor

# Then a spin-orbit coupled spin-unrestricted calculation is performed using the
# collinear approximation. Note that symmetry NOSYM is used.

AMS_JOBNAME=so $AMSBIN/ams <<eor
System
  atoms
     V 0 0 0
     O 0 0 1.589
  End
End

Task SinglePoint

Engine ADF
  ESR
  End
  
  QTens
  
  basis
    core None
    type TZ2P
  End
  
  numericalquality verygood
  
  relativity
    level spin-orbit
    formalism ZORA
    spinorbitmagnetization collinear
  end
  
  SCF
    AccelerationMethod LISTf
  End
  
  symmetry nosym

  Unrestricted
  
  XC
    GGA Becke Perdew
  End
EndEngine

eor