Author Topic: How can get the spin-up and spin-down bands in atk-11.2.0  (Read 4099 times)

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Offline fly

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Recently, I try to use atk-11.2.0.  However, when I test spin-polarized ZGNR, I cannot get the
spin up and spin down bands.  In vnl, I can only find a band picture. The band is the same with spin unpolarized band whatever the intial spin is set AF or FM. Why is this? I have tested other systems, same case is presented. The script is posted as follows:
# -------------------------------------------------------------
# Bulk configuration
# -------------------------------------------------------------

# Set up lattice
vector_a = [10.0, 0.0, 0.0]*Angstrom
vector_b = [0.0, 19.3063, 0.0]*Angstrom
vector_c = [0.0, 0.0, 2.46100171044]*Angstrom
lattice = UnitCell(vector_a, vector_b, vector_c)

# Define elements
elements = [Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon, Carbon,
            Hydrogen, Hydrogen]

# Define coordinates
cartesian_coordinates = [[  5.        ,  13.2053    ,   0.        ],
                         [  5.        ,   6.101     ,   0.        ],
                         [  5.        ,   6.81143   ,   1.23050086],
                         [  5.        ,   8.23229   ,   1.23050086],
                         [  5.        ,   8.94272   ,   0.        ],
                         [  5.        ,  10.36358   ,   0.        ],
                         [  5.        ,  11.07401   ,   1.23050086],
                         [  5.        ,  12.49487   ,   1.23050086],
                         [  5.        ,  14.3063    ,   0.        ],
                         [  5.        ,   5.        ,   0.        ]]*Angstrom

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

# -------------------------------------------------------------
# Calculator
# -------------------------------------------------------------
#----------------------------------------
# Basis Set
#----------------------------------------
basis_set = LDABasis.SingleZetaPolarized

numerical_accuracy_parameters = NumericalAccuracyParameters(
    grid_mesh_cutoff=150.0*Hartree,
    )

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

bulk_configuration.setCalculator(calculator)

# -------------------------------------------------------------
# Initial State
# -------------------------------------------------------------
initial_spin = InitialSpin(scaled_spins=[1.0, -1.0, -1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0])
bulk_configuration.setCalculator(
    calculator,
    initial_spin=initial_spin,
)
bulk_configuration.update()
nlsave('analysis.nc', bulk_configuration)
nlprint(bulk_configuration)

# -------------------------------------------------------------
# Bandstructure
# -------------------------------------------------------------
bandstructure = Bandstructure(
    configuration=bulk_configuration,
    route=['G', 'Z'],
    points_per_segment=20,
    bands_above_fermi_level=All
    )
nlsave('analysis.nc', bandstructure)

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Re: How can get the spin-up and spin-down bands in atk-11.2.0
« Reply #1 on: April 19, 2011, 10:24 »
Contrary to earlier versions, in 11.2 you must explicitly choose a spin-polarized exchange-correlation potential to get a spin-polarized calculation.