mirror of https://github.com/phonopy/phonopy.git
62 lines
2.0 KiB
ReStructuredText
62 lines
2.0 KiB
ReStructuredText
.. _siesta_interface:
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Siesta & phonopy calculation
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=========================================
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Supported Siesta tags
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---------------------------
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Currently phonopy can read the siesta tags listed below.
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More tags may be supported on request.
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::
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AtomicCoordinatesFormat, ChemicalSpeciesLabel, AtomicCoordinatesFormat,
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AtomicCoordinatesAndAtomicSpecies, LatticeVectors
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How to run
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----------
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The procedure of a Siesta-phonopy calculation is the following:
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1) Read a Siesta input file and create supercells with
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:ref:`siesta_mode` option::
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% phonopy --siesta -d --dim="2 2 2" -c Si.fdf
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In this example, 2x2x2 supercells are created. ``supercell.fdf`` and
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``supercell-xxx.fdf`` (``xxx`` are numbers) give the perfect
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supercell and supercells with displacements, respectively. In these
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supercell files, lines only relevant to crystal structures are
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generated. ``phonopy_disp.yaml`` is also created. This file contains
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information on displacements. Perhaps the supercell files are
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stored in ``disp-xxx`` directories, then Siesta calculations are
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executed in these directories.
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2) Calculate forces on atoms in the supercells with
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displacements. Calculation specification tags have to be added to
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``supercell-xxx.in`` files. Crystal structure is not allowed to relax
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in the force calculations, because atomic forces induced by a small
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atomic displacement are what we need for the phonon calculation.
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3) Create ``FORCE_SETS`` by
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::
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% phonopy --siesta -f disp-001/Si.FA ...
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Here ``*.FA`` files are the forces files created by Siesta.
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To run this command, ``phonopy_disp.yaml`` has to be
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located in the current directory because the atomic displacements are
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written into the FORCE_SETS file. An example is found in
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``example/Si-siesta``.
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4) Run post-process of phonopy with the Siesta input file for the
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unit cell used in the step 1::
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% phonopy --siesta -c Si.fdf -p band.conf
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or::
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% phonopy --siesta -c Si.fdf --dim="2 2 2" [other-OPTIONS] [setting-file]
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