lattice = FaceCenteredCubic(5.6537*Angstrom)
elements = [Gallium, Arsenic]
fractional_coordinates = [[ 0.  ,  0.  ,  0.  ],
                                  [ 0.25,  0.25,  0.25]]

bulk_configuration = BulkConfiguration(
    bravais_lattice=lattice,
    elements=elements,
    fractional_coordinates=fractional_coordinates
    )

# -------------------------------------------------------------
# Calculator
# -------------------------------------------------------------
k_point_sampling = MonkhorstPackGrid(7, 7, 7)

numerical_accuracy_parameters = NumericalAccuracyParameters(
            k_point_sampling=k_point_sampling,
                )

calculator = LCAOCalculator(
            numerical_accuracy_parameters=numerical_accuracy_parameters,
                )

bulk_configuration.setCalculator(calculator)
bulk_configuration.update()

# -------------------------------------------------------------
# ProjectedDensityOfStates
# -------------------------------------------------------------
pdos = ProjectedDensityOfStates(
    configuration=bulk_configuration,
    projections=ProjectOnShellsByElement,
    kpoints=MonkhorstPackGrid(11, 11, 11),
    energies=numpy.arange(-4.0, 4.0, 0.01) * eV
    )