# -*- coding: utf-8 -*-
# -------------------------------------------------------------
# Bulk Configuration
# -------------------------------------------------------------

# Set up lattice
lattice = FaceCenteredCubic(3.61496*Angstrom)

# Define elements
elements = [Copper]

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

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

# -------------------------------------------------------------
# Calculator
# -------------------------------------------------------------
k_point_sampling = MonkhorstPackGrid(
    na=7,
    nb=7,
    nc=7,
    )
numerical_accuracy_parameters = NumericalAccuracyParameters(
    k_point_sampling=k_point_sampling,
    density_mesh_cutoff=200.0*Hartree,
    )

calculator = PlaneWaveCalculator(
    wave_function_cutoff=50.0*Hartree,
    numerical_accuracy_parameters=numerical_accuracy_parameters,
    )
bulk_configuration.setCalculator(calculator)
nlprint(bulk_configuration)
bulk_configuration.update()
nlsave('cu-bulk.hdf5', bulk_configuration)

# -------------------------------------------------------------
# Optimize Geometry
# -------------------------------------------------------------
bulk_configuration = OptimizeGeometry(
    bulk_configuration,
    max_forces=0.05*eV/Ang,
    max_stress=0.1*GPa,
    max_steps=200,
    max_step_length=0.2*Ang,
    trajectory_filename=None,
    optimizer_method=LBFGS(),
    constrain_bravais_lattice=True,
)
nlsave('cu-bulk.hdf5', bulk_configuration)
nlprint(bulk_configuration)

# -------------------------------------------------------------
# Bandstructure
# -------------------------------------------------------------
bandstructure = Bandstructure(
    configuration=bulk_configuration,
    route=['G', 'X', 'W', 'L', 'G', 'K', 'X', 'U', 'W', 'K', 'L'],
    points_per_segment=200
    )
nlsave('cu-bulk.hdf5', bandstructure)

# -------------------------------------------------------------
# Total Energy
# -------------------------------------------------------------
total_energy = TotalEnergy(bulk_configuration)
nlsave('cu-bulk.hdf5', total_energy)
nlprint(total_energy)