erbium_6s = SlaterOrbital(
    principal_quantum_number=6,
    angular_momentum=0,
    slater_coefficients=[ 1.408*1/Bohr ],
    weights=[ 1.0 ]
    )

erbium_6p = SlaterOrbital(
    principal_quantum_number=6,
    angular_momentum=1,
    slater_coefficients=[ 1.306*1/Bohr ],
    weights=[ 1.0 ]
    )

erbium_5d = SlaterOrbital(
    principal_quantum_number=5,
    angular_momentum=2,
    slater_coefficients=[ 2.199*1/Bohr ],
    weights=[ 1.0 ]
    )

erbium_4f = SlaterOrbital(
    principal_quantum_number=4,
    angular_momentum=3,
    slater_coefficients=[ 5.96*1/Bohr ],
    weights=[ 1.0 ]
    )

ErbiumBasis = HuckelBasisParameters(
    element=PeriodicTable.Erbium,
    orbitals=[ erbium_6s , erbium_6p , erbium_5d , erbium_4f ],
    occupations=[ 0.875 , 2.625 , 4.375 , 6.125 ],
    ionization_potential=[ -4.882*eV , -3.545*eV , -6.917*eV , -19.174*eV ],
    onsite_hartree_shift=[ 9.0*eV , 9.0*eV , 9.0*eV , 9.0*eV ],
    onsite_spin_split=[[-0.2829, -0.15128, -0.1893, -0.012725], [-0.15128, -0.3203, -0.18495, -0.002511], [-0.1893, -0.18495, -0.1854, -0.05557], [-0.012725, -0.002511, -0.05557, -0.4158]]*eV,
    wolfsberg_helmholtz_constant=1.75,
    vacuum_level=0.0*eV,
    )