How to use the abipy.abilab.Structure.from_file function in abipy

def make_ion_ioncell_inputs(paral_kgb=0):
    pseudos = abidata.pseudos("14si.pspnc")
    structure = abilab.Structure.from_file(abidata.cif_file("si.cif"))

    # Perturb the structure (random perturbation of 0.1 Angstrom)
    # then compress the volume to trigger dilatmx.
    #structure.perturb(distance=0.1)
    #structure.scale_lattice(structure.volume * 0.6)

    global_vars = dict(
        ecut=28,
        ngkpt=[4,4,4],
        shiftk=[0,0,0],
        nshiftk=1,
        chksymbreak=0,
        paral_kgb=paral_kgb,
        #prtwf=0,
    )

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_")

    # Initialize structure and pseudos.
    structure = abilab.Structure.from_file(abidata.cif_file("si.cif"))
    pseudos = abidata.pseudos("14si.pspnc")

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

    # Use the ebands_input factory function to build a MultiDataset.
    # keyword args are optional (default values are given or computed automatically, see docs).
    multi = abilab.ebands_input(structure, pseudos, kppa=40, dos_kppa=80,
                                nscf_nband=6, ndivsm=10, ecut=6, spin_mode="unpolarized")

    work = flowtk.BandStructureWork(scf_input=multi[0], nscf_input=multi[1], dos_inputs=multi[2])
    flow.register_work(work)

    return flow

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_")

    # build the structures
    base_structure = abilab.Structure.from_file(data.cif_file("si.cif"))
    modifier = abilab.StructureModifier(base_structure)

    etas = [-0.1, 0, +0.1]
    ph_displ = np.reshape(np.zeros(3*len(base_structure)), (-1,3))
    ph_displ[0,:] = [+1, 0, 0]
    ph_displ[1,:] = [-1, 0, 0]

    displaced_structures = modifier.displace(ph_displ, etas, frac_coords=False)

    flow = flowtk.Flow(options.workdir, manager=options.manager)

    for structure in displaced_structures:
        # Create the work for the band structure calculation.
        scf_input, nscf_input = make_scf_nscf_inputs(structure)

        work = flowtk.BandStructureWork(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(__file__).replace(".py", "").replace("run_", "flow_")

    pseudos = abidata.pseudos("14si.pspnc", "8o.pspnc")
    base_structure = abilab.Structure.from_file(abidata.cif_file("si.cif"))

    news, uparams = [], [0.2, 0.3]
    for u in uparams:
        new = special_positions(base_structure.lattice, u)
        news.append(new)

    flow = flowtk.Flow(options.workdir, manager=options.manager)

    # Create the list of workflows. Each workflow defines a band structure calculation.
    for new_structure, u in zip(news, uparams):
        # Generate the workflow and register it.
        flow.register_work(make_workflow(new_structure, pseudos))

    return flow

def make_relax_flow(structure_file=None):
    """
    Build and return a flow that perform a structural relaxation for different k-point samplings.
    """
    ngkpt_list = [[3, 3, 2], [6, 6, 4], [8, 8, 6]]

    if structure_file is None:
        structure = abilab.Structure.from_file(abidata.cif_file("gan2.cif"))
    else:
        structure = abilab.Structure.from_file(structure_file)

    multi = abilab.MultiDataset(structure=structure, pseudos=get_pseudos(structure), ndtset=len(ngkpt_list))

    # Add mnemonics to input file.
    multi.set_mnemonics(True)

    # Global variables
    multi.set_vars(
        ecut=20,
        tolrff=5.0e-2,
        nstep=30,
        optcell=2,
        ionmov=3,
        ntime=50,
        dilatmx=1.05,
        ecutsm=0.5,

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_")

    # Initialize pseudos and Structure.
    pseudos = abidata.pseudos("14si.pspnc")
    structure = abilab.Structure.from_file(abidata.cif_file("si.cif"))

    kppa = scf_kppa = 1
    nscf_nband = 6
    nscf_ngkpt = [4, 4, 4]
    nscf_shiftk = [0.1, 0.2, 0.3]
    bs_loband = 2
    bs_nband = nscf_nband
    mbpt_sciss = 0.7 * abilab.units.eV_to_Ha
    mdf_epsinf = 12
    ecuteps = 2
    ecut = 12

    flow = flowtk.Flow(workdir=options.workdir, manager=options.manager)

    # BSE calculation with model dielectric function.
    multi = abilab.bse_with_mdf_inputs(

def make_eos_flow(structure_file=None):
    """
    Build and return a Flow to compute the equation of state
    of an isotropic material for different k-point samplings.
    """
    scale_volumes = np.arange(94, 108, 2) / 100.

    if structure_file is None:
        structure = abilab.Structure.from_file(abidata.cif_file("si.cif"))
    else:
        structure = abilab.Structure.from_file(structure_file)

    multi = abilab.MultiDataset(structure=structure, pseudos=get_pseudos(structure), ndtset=len(scale_volumes))

    # Global variables
    multi.set_vars(
        ecut=16,
        tolvrs=1e-16
    )

    multi.set_kmesh(ngkpt=[4, 4, 4], shiftk=[[0.5, 0.5, 0.5], [0.5, 0.0, 0.0], [0.0, 0.5, 0.0], [0.0, 0.0, 0.5]])

    for idt, scal_vol in enumerate(scale_volumes):
        new_lattice = structure.lattice.scale(structure.volume*scal_vol)

def make_inputs(paw=False):
    # Crystalline silicon
    # Calculation of the GW correction to the direct band gap in Gamma
    # Dataset 1: ground state calculation
    # Dataset 2: NSCF calculation
    # Dataset 3: calculation of the screening
    # Dataset 4: calculation of the Self-Energy matrix elements (GW corrections)
    structure = abilab.Structure.from_file(abidata.cif_file("si.cif"))
    pseudos = abidata.pseudos("14si.pspnc") if not paw else abidata.pseudos("Si.GGA_PBE-JTH-paw.xml")

    multi = abilab.MultiDataset(structure, pseudos=pseudos, ndtset=4)

    ecut = 24
    multi.set_vars(
        ecut=ecut,
        pawecutdg=ecut*4 if paw else None,
        timopt=-1,
        istwfk="*1",
        paral_kgb=0,
    )

    gs, nscf, scr, sigma = multi.split_datasets()

    # This grid is the most economical, but does not contain the Gamma point.

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(__file__).replace(".py", "").replace("run_", "flow_")

    # Initialize pseudos and Structure.
    pseudos = abidata.pseudos("14si.pspnc")
    structure = abilab.Structure.from_file(abidata.cif_file("si.cif"))

    kppa = scf_kppa = 1
    nscf_nband = 6
    nscf_ngkpt = [4, 4, 4]
    nscf_shiftk = [0.1, 0.2, 0.3]
    bs_loband = 2
    bs_nband = nscf_nband
    mbpt_sciss = 0.7 * abilab.units.eV_to_Ha
    mdf_epsinf = 12
    ecuteps = 2
    ecut = 12

    flow = flowtk.Flow(workdir=options.workdir, manager=options.manager)

    # BSE calculation with model dielectric function.
    multi = abilab.bse_with_mdf_inputs(