Configuration File

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

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:\(^{-3}\)).

• 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 \(\mu_B\) or \(c_s^2 > 1\)) 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.