==========================
Parameters for auto-kappa
==========================

.. contents:: Contents
   :local:
   :depth: 1
   

.. _sec_params_ak_recommendations:

Recommendations for parameters
================================

.. csv-table:: Default and recommended parameters for VASP
    :file: ./files/recommended_ak_params.csv
    :header-rows: 1
    :align: center
    :width: 100%
    :widths: 20 15 15 50


.. _sec_params_ak_brief:

Brief description
==================

Please see :ref:`sec_params_ak_detailed` for details of each parameter.

Input/Output
-------------

- ``--file_structure``, ``--otudir``: Input structure and output directories

Parallel calculations and commands
-----------------------------------

- ``nprocs``, ``mpirun``: Parameters for parallel calculations

- ``command_{vasp/vasp_gam/alm/anphon/anphon_ver2}``: Commands for VASP and ALAMODE

Accuracy
---------

- ``k_length``: k-point mesh for VASP calculations (`official page <https://www.vasp.at/wiki/index.php/KPOINTS>`_)

- ``nsw_params``: NSW for relaxation calculations

- ``cutoff_cubic``, ``min_nearest``: Cutoff distance for cubic FCs in unit of Å or nearest neighbors

- ``volume_relaxation``: Whether to perform relaxation calculation with the Birch-Murnaghan equation of state

Supercell size
--------------

- ``analyze_with_larger_supercell``, ``max_loop_for_largesc``: 
  Whether to analyze with larger supercells when imaginary frequencies occur, and the maximum number of loops

- ``max_natoms``, ``delta_max_natoms``: Maximum number of atoms allowed in supercells

Displacement
-------------

- ``nmax_suggest``: 
  Threshold of suggested displacement patterns (:math:`N_{sugget}`) for the finite-displacement approach.
  If :math:`N_{suggest}` exceeds ``nmax_suggest``, LASSO regression is applied.

- ``frac_nrandom``, ``frac_nrandom_higher``: Fractional number of random displacement patterns

- ``mag_harm``, ``mag_cubic``, ``random_disp_temperature``: 
  Displacement magnitudes for harmonic, cubic, and higher-order FCs
  
Beyond three phonon scattering
-------------------------------

- ``scph``, ``four``: Self-consistent phonon (SCPH) approach and four-phonon scattering processes

- ``frac_kdensity_4ph``: q-point mesh for four-phonon scattering processes

Utilities
----------

- ``calculate_forces``: This option is useful to analyze single material with multiple machines 
  while ``auto-kappa`` is available on single node only.
  If this flag is 0, the relaxation calculation is performed and the structures with displacements are generated, 
  but the force calculations are not performed. You can perform the force calculations with multiple machines.

- ``harmonic_only``: Whether to calculate harmonic FCs only

Others
-------

- ``nonanalytic``, ``negative_freq``, ``vasp_parameters``


.. _sec_params_ak_detailed:


Detailed description
=====================

.. argparse::
    :module: auto_kappa.cui.ak_parser
    :func: get_parser
    :prog: auto-kappa