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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
Ba_opt.dat and
Babcc_opt.dat.
Since Ba_CA19.vps and Ba_PBE19.vps include the 5s, 5p, and 6s states (10 electrons)
as the valence states, the minimal basis set is Ba*.*-s2p1.
Our recommendation for the choice of cutoff radius of basis functions is that
Ba10.0.pao is enough for bulks, but Ba12.0.pao or Ba14.0.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 Ba10.0-s3p2d2f2 and Ba10.0-s3p3d3f2
in the total energy at the minimum point is 0.0033 eV/atom.
An input file used for the OpenMX calculations can be found at
Babcc-EvsV.dat.
For comparison the result by the Wien2k code is also shown, where
the calculation was performed by default setting in the Ver. 9.1 of Wien2k except for
the use of R_{MT} x K_{MAX} of 12, for the spherical harmonic truncation
lmax=12 inside the muffin-tin spheres, and lmax=6 outside of the muffin-tin sphere.

**(2) Calculations of the band dispersion in the bcc structure,**
where the non-spin polarized collinear calculation with the lattice constant of 5.020 Ang.
was performed using Ba_PBE19.vps and Ba10.0-s3p2d2f2,
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
Babcc-Band.dat .
For comparison the result by the Wien2k code is also shown, where
the calculation was performed by default setting in the Ver. 9.1 of Wien2k
except for
the use of R_{MT} x K_{MAX} of 12, for the spherical harmonic truncation
lmax=12 inside the muffin-tin spheres, and lmax=6 outside of the muffin-tin sphere.