from ATK.KohnSham import *

# Create example structure
Iron = BulkConfiguration(
    bravais_lattice=BodyCenteredCubic(2.87*Angstrom),
    elements=[Iron],
    cartesian_coordinates=[3*(0.0,)]*Angstrom
    )
# K-points must be specified for bulk calculations
kpoints = brillouinZoneIntegrationParameters((10,10,10))

# Specify spin-polarized electron density
initial_density = electronDensityParameters(
    initial_scaled_spin=[1.0]
    )

# Configure and perform actual calculation
method = KohnShamMethod(
    electron_density_parameters=initial_density,
    brillouin_zone_integration_parameters=kpoints,
    )

scf_iron = method.apply(Iron)

# Increase verbosity when reporting
# Mulliken populations
import ATK
ATK.setVerbosityLevel(10)
print calculateMullikenPopulation(scf_iron).toArray()