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 antiferrmagnetic density.

For antiferromagnetic iron we need a larger unit cell of two atoms. Because 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
    angle Degree
END

ATOMS Fe
     0.0 0.0 0.0
end

! second iron as new type to break the symmetry
Atoms Fe
   -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
eor