Example 5: Get 3D NLTE correction
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About
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This example will show you how to find the 3D NLTE correction for a 1D LTE abundance by using the ``Nlte`` class in ``breidablik.interpolate.nlte``.

Example
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Lets assume we want to find the 3D NLTE correction for a 1D LTE abundance of 2.2 dex for LP 815-43.

::

  abund_1DLTE = 2.2 # dex
  # stellar parameters for LP 815-43
  t_eff = 6400 # K
  log_g = 4.17 # cgs
  met = -2.74 # dex

Next, we load in the models by initialising the class, then call the function ``nlte_correction`` with the parameters we just defined.

::

  from breidablik.interpolate.nlte import Nlte
  # initialise model
  model = Nlte()
  # find 3D NLTE correction
  nltec = model.nlte_correction(t_eff, log_g, met, abund_1DLTE)
  print(nltec)

Which returns a correction of -0.00768 dex.

``nlte_correction`` accepts a parameter: ``center``, that determines which model is used: there are 3 models, 1 for each Li line. The 3 lithium lines are centered at 610.5298, 670.9659, and 812.8606 nm. The input ``center`` value will snap to the closest value out of those 3. By default, the 670.9 nm model is used.