mirror of https://github.com/phonopy/phono3py.git
86 lines
3.1 KiB
Markdown
86 lines
3.1 KiB
Markdown
(turbomole_interface)=
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# TURBOMOLE & phono3py calculation
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The riper module of TURBOMOLE can be used to study periodic structures.
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An example for TURBOMOLE is found in the `example/Si-TURBOMOLE` directory.
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To invoke the TURBOMOLE interface, `--turbomole` option has to be always
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specified:
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```bash
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% phono3py --turbomole [options] [arguments]
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```
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When the file name of the unit cell is different from the default one
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(see :ref:`default_unit_cell_file_name_for_calculator`), `-c` option
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is used to specify the file name. TURBOMOLE unit cell file parser used in
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phono3py is the same as that in phonopy. It reads a limited number of
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keywords that are documented in the phonopy web site
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(http://phonopy.github.io/phonopy/turbomole.html#turbomole-interface).
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(turbomole_workflow)=
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## Workflow
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In the example Si-TURBOMOLE, the TURBOMOLE input file is `control`.
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This is the default file name for the TURBOMOLE interface,
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so the `-c control` parameter is not needed.
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1) Create supercells with displacements (2x2x2 conventional cell for
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3rd order FC and 3x3x3 conventional cell for 2nd order FC)
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```bash
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% phono3py --turbomole --dim="2 2 2" --dim-fc2="3 3 3" -d
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```
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111 supercell directories (`supercell-00xxx`) for the third order
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force constants are created. In addition, one supercell directory
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(`supercell_fc2-00001`) is created for the second order
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force constants.
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2) Complete TURBOMOLE inputs need to be prepared manually in the subdirectories.
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Note that supercells with displacements must not be relaxed in the
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force calculations, because atomic forces induced by a small atomic
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displacement are what we need for the phonon calculation. To get accurate
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forces, `$scfconv` should be 10. Phono3py includes this data group automatically
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in the `control` file. You also need to choose a k-point mesh for the force
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calculations. TURBOMOLE data group $riper may need to be adjusted to improve
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SCF convergence (see example files in subdirectory supercell-00001 for
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further details)
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Then, TURBOMOLE supercell calculations are executed to obtain forces on
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atoms, e.g., as follows:
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```bash
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% riper > supercell-00001.out
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```
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3) Collect forces in `FORCES_FC3` and `FORCES_FC2`::
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```bash
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% phono3py --turbomole --cf3 supercell-*
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% phono3py --turbomole --cf2 supercell_fc2-*
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```
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`disp_fc3.yaml` and `disp_fc2.yaml` are used to create `FORCES_FC3` and
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`FORCES_FC2`, therefore they must exist in current directory. The Si-TURBOMOLE
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example contains pre-calculated force files.
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4) Calculate 3rd and 2nd order force constants in files `fc3.hdf5` and `fc2.hdf5`:
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```bash
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% phono3py --turbomole --dim="2 2 2" --dim-fc2="3 3 3" --fc-symmetry
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```
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`--sym-fc` is used to symmetrize second- and third-order force constants.
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5) Thermal conductivity calculation:
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```bash
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% phono3py --turbomole --primitive-axis="0 1/2 1/2 1/2 0 1/2 1/2 1/2 0" --fc3 --fc2 --dim="2 2 2" --dim-fc2="3 3 3" --mesh="20 20 20" --br
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```
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`--primitive-axis` is used to get the results for the primitive 2-atom cell
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`--br` invokes the Relaxation Time Approximation.
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Carefully test the convergence with respect to `--mesh`!
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