# -------------------------------------------------------------
# Bulk Configuration
# -------------------------------------------------------------

# Set up lattice
lattice = FaceCenteredCubic(3.8903*Angstrom)

# Define elements
elements = [Palladium]

# Define coordinates
fractional_coordinates = [[ 0.,  0.,  0.]]

# Set up configuration
bulk_configuration = BulkConfiguration(
    bravais_lattice=lattice,
    elements=elements,
    fractional_coordinates=fractional_coordinates
    )

# -------------------------------------------------------------
# Calculator
# -------------------------------------------------------------
#----------------------------------------
# Basis Set
#----------------------------------------
basis_set = [
    GGABasis.Palladium_DoubleZetaPolarized,
    ]

#----------------------------------------
# Exchange-Correlation
#----------------------------------------
exchange_correlation = GGA.PBE

numerical_accuracy_parameters = NumericalAccuracyParameters(
    k_point_sampling=(9, 9, 9),
    )

calculator = LCAOCalculator(
    basis_set=basis_set,
    exchange_correlation=exchange_correlation,
    numerical_accuracy_parameters=numerical_accuracy_parameters,
    )

bulk_configuration.setCalculator(calculator)
nlprint(bulk_configuration)
bulk_configuration.update()
nlsave('Pd_bulk.nc', bulk_configuration)

# -------------------------------------------------------------
# Optimize Geometry
# -------------------------------------------------------------
bulk_configuration = OptimizeGeometry(
        bulk_configuration,
        max_forces=0.05*eV/Ang,
        max_stress=0.005*eV/Ang**3,
        max_steps=200,
        max_step_length=0.2*Ang,
        trajectory_filename='Pd_bulk.nc',
        optimizer_method=LBFGS(),
        )
nlsave('Pd_bulk.nc', bulk_configuration)
nlprint(bulk_configuration)