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

# Define elements
elements = [Copper]

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

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

# Define the substituting element
substitute = Silver

# Define calculator for pre-optimization calculations.
potentialSet = EAM_AgCu_2009()
calculator_ff = TremoloXCalculator(parameters=potentialSet)

optimize_geometry_parameters = OptimizeGeometryParameters(
    max_forces=0.1*eV/Ang,
    max_step_length=0.2*Ang,
    trajectory_interval=1,
    optimize_cell=True,
    optimizer_method=FIRE(),
    enable_optimization_stop_file=True,
    restart_strategy=NoRestart,
)

training_set = AlloyTrainingParameters(
    reference_configurations=bulk_configuration_copper,
    percentages=[10, 20, 30],
    new_element=substitute,
    algorithm=FixedFraction,
    supercell_repetition=(3, 3, 3),
    rattle=True,
    atomic_rattling_amplitudes=[0.275, 0.4, 0.15] * Angstrom,
    sample_size=60,
    random_seed=667,
    optimize=calculator_ff,
    optimize_geometry_parameters=optimize_geometry_parameters,
)

# -------------------------------------------------------------
# Calculator
# -------------------------------------------------------------
k_point_sampling = KpointDensity(
    density_a=5.0*Angstrom,
    )
numerical_accuracy_parameters = NumericalAccuracyParameters(
    density_mesh_cutoff=100.0*Hartree,
    k_point_sampling=k_point_sampling,
    occupation_method=MethfesselPaxton(0.2*eV, 1),
    )

iteration_control_parameters = IterationControlParameters(
    tolerance=5e-05,
    damping_factor=0.3,
    number_of_history_steps=12,
    max_steps=1000,
    non_convergence_behavior=StopCalculation(),
    )

checkpoint_handler = CheckpointHandler(
    time_interval=1000000.0*Hour,
    )
algorithm_parameters = AlgorithmParameters(
    scf_restart_step_length=0.3*Angstrom,
    )

calculator = LCAOCalculator(
    numerical_accuracy_parameters=numerical_accuracy_parameters,
    iteration_control_parameters=iteration_control_parameters,
    checkpoint_handler=checkpoint_handler,
    algorithm_parameters=algorithm_parameters,
    )

# Set up non-linear coefficients with optimization.
non_linear_coefficients_parameters = NonLinearCoefficientsParameters(
   perform_optimization=True,
   energy_only=False,
)

# Set up parameters to use in the MTP fitting.
fitting_parameters = MomentTensorPotentialFittingParameters(
   basis_size=1000,
   outer_cutoff_radii=4.5*Angstrom,
   mtp_filename='mtp_Cu-Ge_alloy.mtp',
   non_linear_coefficients_parameters=non_linear_coefficients_parameters,
)

# Set up MTP training.
moment_tensor_potential_training = MomentTensorPotentialTraining(
    filename='mtp_study',
    object_id='training',
    training_sets=training_set,
    calculator=calculator,
    calculate_stress=True,
    fitting_parameters_list=fitting_parameters,
    train_test_split=0.8,
    random_seed=13345,
    number_of_processes_per_task=8,
    log_filename_prefix='fit_mtp_Cu-Ge_alloy',
)
moment_tensor_potential_training.update()