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Fully relativistic pseudopotentials

Fully relativistic pseudopotentials generated by
the MBK (PRB 47, 6728 (1993)) scheme within LDA (CA19) and GGA (PBE19) which contain
a partial core correction and fully relativistic effects including spin-orbit coupling.

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Pseudo-atomic orbitals

The number below the symbol means a cutoff radius (a.u.) of the confinement
potential. These file includes fifteen radial parts for each angular
momentum quantum number l (=0,1,2,3). The basis functions were generated by variationally
optimizing the corresponding primitive basis functions in the single atom and the BCC bulk.
The input files used for the orbital optimization can be found at
Fe_opt.dat
and
Febcc_opt.dat .
Since Fe_CA19S.vps and Fe_PBE19S.vps include the 3p, 3d, and 4s states (14 electrons)
as the valence states, the minimal basis set is Fe*.*S-s1p1d1.
Our recommendation for the choice of cutoff radius of basis functions is that
Fe6.0S.pao is enough for bulks, but Fe8.0S.pao or Fe10.0S.pao is preferable
for molecular systems.

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Benchmark calculations by the PBE19 pseudopotential with the various basis functions

**(1) Calculation of the total energy as a function of lattice constant in the bcc structure,**
where the total energy is plotted relative to the minimum energy for each case. a_{0}
and B_{0} are the equilibrium lattice constant and bulk modulus obtained by fitting to
the Murnaghan equation of state. The difference between Fe6.0S-s2p2d1 and Fe6.0S-s3p3d2
in the total energy at the minimum point is 0.0883 eV/atom.
An input file used for the OpenMX calculations can be found at
Febcc-EvsV.dat .
For comparison the result by the Wien2k code is also shown, where
the calculation was performed by default setting in the Ver. 10.1 of Wien2k except for
the use of R_{MT} x K_{MAX} of 14.

**(2) Calculations of the band dispersion in the bcc structure,**
where the spin polarized collinear calculations
with the lattice constant of 2.87 Ang.
were performed using Fe_PBE19S.vps and Fe6.0S-s2p2d1,
and the origin of the energy is taken to be the Fermi level.
The input file used for the OpenMX calculations can be found at
Febcc-Band.dat . The magnetic moment per atom is
also shown in the figures.
For comparison the result by the Wien2k code is also shown, where
the calculation was performed by default setting in the Ver. 10.1 of Wien2k
except for the use of R_{MT} x K_{MAX} of 14.