.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "flow_gallery/run_from_files.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        Click :ref:`here <sphx_glr_download_flow_gallery_run_from_files.py>`
        to download the full example code or to run this example in your browser via Binder

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_flow_gallery_run_from_files.py:


Starting a Flow from external files
===================================

This example shows how to build a flow for Nscf calculations
in which the dependency is given by an external density file.

.. GENERATED FROM PYTHON SOURCE LINES 9-99



.. image:: /flow_gallery/images/sphx_glr_run_from_files_001.png
    :alt: run from files
    :class: sphx-glr-single-img





.. code-block:: default

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


    def make_scf_nscf_inputs(paral_kgb=1):
        """Returns two input files: GS run and NSCF on a high symmetry k-mesh."""
        multi = abilab.MultiDataset(structure=abidata.cif_file("si.cif"),
                                    pseudos=abidata.pseudos("14si.pspnc"), ndtset=2)

        # Global variables
        ecut = 6
        global_vars = dict(
            ecut=ecut,
            nband=8,
            nstep=15,
            paral_kgb=paral_kgb,
        )

        if multi.ispaw:
            global_vars.update(pawecutdg=2*ecut)

        multi.set_vars(global_vars)

        # Dataset 1 (GS run)
        multi[0].set_kmesh(ngkpt=[8, 8, 8], shiftk=[0, 0, 0])
        multi[0].set_vars(tolvrs=1e-6)

        # Dataset 2 (NSCF run)
        kptbounds = [
            [0.5, 0.0, 0.0], # L point
            [0.0, 0.0, 0.0], # Gamma point
            [0.0, 0.5, 0.5], # X point
        ]

        multi[1].set_kpath(ndivsm=6, kptbounds=kptbounds)
        multi[1].set_vars(tolwfr=1e-12)

        # 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_")

        # Get the SCF and the NSCF input.
        scf_input, nscf_input = make_scf_nscf_inputs()

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

        # Create a Work, all tasks in work will start from the DEN file.
        # Note that the file must exist when the work is created
        # Use the standard approach based on tasks and works if
        # there's a node who needs a file produced in the future.
        work = flowtk.Work()
        den_filepath = abidata.ref_file("si_DEN.nc")
        work.register_nscf_task(nscf_input, deps={den_filepath: "DEN"})
        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())


.. rst-class:: sphx-glr-timing

   **Total running time of the script:** ( 0 minutes  0.308 seconds)


.. _sphx_glr_download_flow_gallery_run_from_files.py:


.. only :: html

 .. container:: sphx-glr-footer
    :class: sphx-glr-footer-example


  .. container:: binder-badge

    .. image:: images/binder_badge_logo.svg
      :target: https://mybinder.org/v2/gh/abinit/abipy/gh-pages?filepath=notebooks/flow_gallery/run_from_files.ipynb
      :alt: Launch binder
      :width: 150 px


  .. container:: sphx-glr-download sphx-glr-download-python

     :download:`Download Python source code: run_from_files.py <run_from_files.py>`



  .. container:: sphx-glr-download sphx-glr-download-jupyter

     :download:`Download Jupyter notebook: run_from_files.ipynb <run_from_files.ipynb>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_