Band structure w/wo magnetization

Calculation of the band structure of Fe with and without magnetization. See also <~abinit/tutorial/Input/tspin_1.in>

import os
import sys
import abipy.data as data
import abipy.abilab as abilab
import abipy.flowtk as flowtk


def make_scf_nscf_inputs(nsppol, paral_kgb=1):
    """
    Generate two input files for the GS and the NSCF run for given `nsppol`.
    """
    # Fe normal bcc structure for test of a ferromagnetic calculation
    multi = abilab.MultiDataset(structure=data.structure_from_ucell("Fe-fm"),
                                pseudos=data.pseudos("26fe.pspnc"), ndtset=2)

    # Global variables
    global_vars = dict(
        nsppol=nsppol,
        ecut=18,
        nband=8,
        occopt=3,
        tsmear=0.01,
        paral_kgb=paral_kgb,
    )
    if nsppol == 2:
        global_vars.update(spinat=[0.0, 0.0, 4.0])

    multi.set_vars(global_vars)

    # Dataset 1 (GS run)
    multi[0].set_kmesh(ngkpt=[4,4,4], shiftk=[0.5,0.5,0.5])
    multi[0].set_vars(tolvrs=1e-6)

    # Dataset 2 (NSCF run)
    multi[1].set_kpath(ndivsm=4)
    multi[1].set_vars(tolwfr=1e-8)

    # Generate two input files for the GS and the NSCF run
    scf_input, nscf_input = multi.split_datasets()

    return scf_input, nscf_input


def build_flow(options):
    # Working directory (default is the name of the script with '.py' removed and "run_" replaced by "flow_")
    if not options.workdir:
        options.workdir = os.path.basename(sys.argv[0]).replace(".py", "").replace("run_", "flow_")

    # Create the Flow.
    flow = flowtk.Flow(options.workdir, manager=options.manager)

    # Create the task defining the calculation and run and register it in the flow
    for nsppol in [1, 2]:
        scf_input, nscf_input = make_scf_nscf_inputs(nsppol)
        work = flowtk.BandStructureWork(scf_input, nscf_input)
        flow.register_work(work)

    return flow


# This block generates the thumbnails in the AbiPy gallery.
# You can safely REMOVE this part if you are using this script for production runs.
if os.getenv("READTHEDOCS", False):
    __name__ = None
    import tempfile
    options = flowtk.build_flow_main_parser().parse_args(["-w", tempfile.mkdtemp()])
    build_flow(options).graphviz_imshow()


@flowtk.flow_main
def main(options):
    """
    This is our main function that will be invoked by the script.
    flow_main is a decorator implementing the command line interface.
    Command line args are stored in `options`.
    """
    return build_flow(options)


if __name__ == "__main__":
    sys.exit(main())

Run the script with:

run_fe_ebands -s

then use:

abirun.py flow_fe_ebands ebands -p

to analyze all the band structures produced by the Flow and plot the data