Example: Spin polarization: antiferromagnetic iron¶

#! /bin/sh

# By setting 'Unrestricted Yes' we do a spin polarized calculation. Normally
# this would converge to the ferromagnetic solution.

# With the SpinFlipRegion keyword we make sure that we start with an antiferromagnetic
# density.

# For antiferromagnetic iron we need a larger unit cell of two atoms. Since
# these atoms appear to the program as symmetry equivalent we have to specify
# them as separate types.

$AMSBIN/ams <<eor

Task SinglePoint

System
  Atoms 
    Fe   0.0    0.0    0.0
    Fe  -1.435 -1.435  1.435 region=flip
  end

  Lattice
     -1.435  1.435  1.435
      1.435 -1.435  1.435
      2.87   2.87  -2.87
  End
End

Engine Band
  Title Beta iron

  Convergence
     Criterion 1.0e-4
     SpinFlipRegion flip # Flip (startup) spin density at second atom
  End

  Unrestricted Yes

  Print AtomicChargesDetails
EndEngine
eor