#! /bin/sh


# This calculation shows a spin-flip restart feature that allows to exchange
# alpha and beta fit coefficients for selected atoms upon restart. First the
# high spin configuration with 8 more alpha-electrons than beta-electrons is
# calculated (S_z=4). Next the broken spin-symmetry configuration is calculated
# (S_z=0), using the subkey spinflip in the restart key. In this case the spin
# will be flipped for iron atoms 1 and 2. Note that the used symmetry C(2v) is
# lower than the actual symmetry T(d), such that iron atoms 1 and 2 can have a
# different spin than iron atoms 3 and 4.


AMS_JOBNAME=HighSpin $AMSBIN/ams <<eor
System
  atoms
     Fe      -0.000000000000      -1.256142548900       0.888226914500
     Fe       0.000000000000       1.256142548900       0.888226914500
     Fe      -1.256142548900       0.000000000000      -0.888226914500
     Fe       1.256142548900      -0.000000000000      -0.888226914500
     S       -1.845393493800       0.000000000000       1.304890253400
     S        1.845393493800      -0.000000000000       1.304890253400
     S       -0.000000000000      -1.845393493800      -1.304890253400
     S        0.000000000000       1.845393493800      -1.304890253400
  End
End

Task SinglePoint

Engine ADF
  Title Fe4S4 High-spin configuration

  Unrestricted Yes
  SpinPolarization 8.0

  symmetry C(2v)

  XC
    GGA OPBE
  End

  ! Omit printing of SFOs, populations, etc. since they may change per computer
  ! In real-life calculations you may want to have them
  NoPrint SFO SCF FIT NUMINT MDC DensityAtNucleus
EndEngine
eor


AMS_JOBNAME=LowSpin $AMSBIN/ams <<eor
System
  atoms
     Fe      -0.000000000000      -1.256142548900       0.888226914500
     Fe       0.000000000000       1.256142548900       0.888226914500
     Fe      -1.256142548900       0.000000000000      -0.888226914500
     Fe       1.256142548900      -0.000000000000      -0.888226914500
     S       -1.845393493800       0.000000000000       1.304890253400
     S        1.845393493800      -0.000000000000       1.304890253400
     S       -0.000000000000      -1.845393493800      -1.304890253400
     S        0.000000000000       1.845393493800      -1.304890253400
  End
End

Task SinglePoint

EngineRestart HighSpin.results/adf.rkf

Engine ADF
  Title Fe4S4 low-spin configuration

  Restart
    SpinFlip 1 2
  End

  Unrestricted Yes
  SpinPolarization 0.0

  symmetry C(2v)
  
  XC
    GGA OPBE
  End
EndEngine
eor