Example: Spin polarization: antiferromagnetic iron¶

Download BetaIron.run

With the UNRESTRICTED keyword we do a spin polarized calculation. Normally this would converge to the ferromagnetic solution.

With the SpinFlip 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.

$ADFBIN/band << eor

TITLE Beta iron

UNITS
    length Angstrom
END

! The two iron atoms have different "types" to break the symmetry
ATOMS
  Fe.a   0.0    0.0    0.0
  Fe.b  -1.435 -1.435  1.435
end

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

CONVERGENCE
   CRITERION 1.0e-4
   Degenerate default
   SpinFlip 2  ! Flip (startup) spin density at second atom
END

BasisDefaults
   BasisType DZ
   Core Large
End

UNRESTRICTED

end input
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