Configuration File
==================

The `config.yaml` file provides the configuration parameters for the MetaModel module. 
An example of a configuration file is shown below:

.. code-block:: yaml

  model_regime: 'non-relativistic'
  bulk_properties:
    BE: -15.97
    Esym: 32.01
    K0: 230.0
    Ksym: -120.0
    Lsym: 46.0
    Q0: -225.0
    Qsym: 350.0
    Z0: -443.0
    Zsym: -690.0
    b0: 6.9
    bsym: 0.0
    meff_norm: 0.89
    meff_splitting: 0.0
    n0: 0.1595
    parametrization: ''
  grid:
    delta_grid: linear
    delta_max: 1.0
    delta_min: 0.0
    delta_points: 10
    nB_grid: linear
    nB_max: 0.8
    nB_min: 0.05
    nB_points: 25
  
In the following, we describe the various configuration parameters available.

General Settings
----------------

- **model_regime**: *(string, default: "non-relativistic")*  

  Options are `relativistic` and `non-relativistic`. 

Bulk Properties
---------------

- **BE**: *(float, default: -15.97)*  

  Binding energy per nucleon at saturation density (in MeV).

- **n0**: *(float, default: 0.1595)*  

  Saturation density (in fm::math:`^{-3}`).

- **K0**: *(float, default: 230.0)*  

  Incompressibility at saturation density (in MeV).

- **Q0**: *(float, default: -225.0)*

  Skewness at saturation density (in MeV).

- **Z0**: *(float, default: -443.0)*

  Kurtosis at saturation density (in MeV).

- **Esym**: *(float, default: 32.01)*  

  Symmetry energy at saturation density (in MeV).       

- **Lsym**: *(float, default: 46.0)*

  Slope of the symmetry energy at saturation density (in MeV).

- **Ksym**: *(float, default: -120.0)*

  Curvature of the symmetry energy at saturation density (in MeV).

- **Qsym**: *(float, default: 350.0)*

  Skewness of the symmetry energy at saturation density (in MeV).

- **Zsym**: *(float, default: -690.0)*
    
  Kurtosis of the symmetry energy at saturation density (in MeV).

- **b0**: *(float, default: 6.9)*
  
  Parameter for the low density exponential correction in symmetric nuclear matter.

- **bsym**: *(float, default: 0.0)*

  Parameter for the low density exponential correction in the symmetry energy.
    
- **meff_norm**: *(float, default: 0.89)*
    
  Effective mass at saturation density, normalized to the nucleon mass.

- **meff_splitting**: *(float, default: 0.0)*

  Effective mass splitting at saturation density (in MeV).

- **parametrization**: *(string, default: "")*

  Selects a named EOS parametrization (options: `SLy4`, `SLy4_bar`, `RATP`, `SKI4`, `NL3`)
  instead of specifying ``bulk_properties`` manually. When set to one of these names, all
  other ``bulk_properties`` fields above are ignored and the corresponding parameters are
  looked up instead. Leave as ``''`` or ``none`` to use the explicit bulk properties above.

  .. note::

     Not every named parametrization is well-behaved across the full density range with
     both ``model_regime`` options — e.g. ``SLy4`` with ``model_regime: relativistic``
     becomes numerically unstable above roughly twice the saturation density, while it is
     well-behaved with ``model_regime: non-relativistic``. Check ``status.yaml`` and the
     output EOS for signs of instability (e.g. negative :math:`\mu_B` or :math:`c_s^2 > 1`)
     if you use a named parametrization outside its validated regime.

Grid Settings
-------------

- **nB_grid**: *(string, default: "linear")*  

  Grid type for the baryon density. Options are `linear` and `log`.

- **nB_min**: *(float, default: 0.005)*
    
  Minimum baryon density (in fm:math:`^{-3}`).

- **nB_max**: *(float, default: 0.8)*

  Maximum baryon density (in fm:math:`^{-3}`).

- **nB_points**: *(int, default: 40)*

  Number of points in the baryon density grid.

- **delta_grid**: *(string, default: "linear")*
  
  Grid type for the isospin asymmetry. Options are `linear` and `log`.

- **delta_min**: *(float, default: 0.0)*    

  Minimum isospin asymmetry.

- **delta_max**: *(float, default: 1.0)*

  Maximum isospin asymmetry.

- **delta_points**: *(int, default: 1)*

  Number of points in the isospin asymmetry grid.