use_api_mphys.md

 ## MPHYS API
 [MPHYS](https://github.com/openMDAO/MPHYS) (Multi-PHYSics) is a framework designed to perform multi-physics analysis and optimization, and is built on top of [openMDAO](https://openmdao.org/). The API allows to interface DART with other software through MPHYS, and is implemented under [api/mphys](https://gitlab.uliege.be/am-dept/dartflo/blob/master/dart/api/mphys.py).
 
-**0. Importing the modules**  
-Since MPHYS couples multiple software, it is required to install them before using MPHYS. As such, DART cannot be used from a development environement (it must be installed), and must be imported by calling,
+**0. Importing the API**  
+Since MPHYS couples multiple software, it is required to install them before using MPHYS. As such, DART cannot be used from a development environment (it must be installed), and must be imported by calling,
 ```python
 from dartflo.dart.api.mphys import DartBuilder
 ```
-Additionaly, the interface must be setup in an MPHYS class,
+
+**1. Initializing the interface**  
+In practise, the MPHYS API uses the [Core API](use_api_core) to initialize DART. Note that the interface must be setup in an MPHYS class,
 ```python
 from mphys import Multipoint
 class Top(Multipoint):
-    ...
+    # ...
+    dart = DartBuilder(p, scenario=..., task=...)
 ```
+where `p` is a dictionary of parameters (available choices are listed in [core](use_api_core)), and where valid choices for `scenario` are `'aerodynamic'` or `'aerostructural'`, and valid choices for `task` are `'analysis'` or `'optimization'`.
 
-**1. Defining the parameters**  
-The list of parameters required to setup the interface is essentialy a simplified version of that used for the internal API. Parameters are listed hereunder:
-```python
-p = {
-    # Options
-    'Threads' : int, # number of threads
-    'Verb' : int, # verbosity
-    # Model (geometry or mesh)
-    'File' : str, # Input file containing the model
-    'Pars' : dict, # parameters for input file model
-    'Dim' : int, # problem dimension (2 or 3)
-    'Format' : str, # save format (vtk or gmsh)
-    # Markers...
-    'Fluid' : str, # name of physical group containing the fluid
-    'Farfield' : list of str, # LIST of names of physical groups containing the farfield boundaries (downstream should be last element)
-    # ... only 2D
-    'Wing' : str, # name of physical group containing the airfoil boundary
-    'Wake' : str, # name of physical group containing the wake
-    'Te' : str, # name of physical group containing the trailing edge
-    # ... only 3D
-    'Wings' : list of str, # LIST of names of physical groups containing the lifting surface boundary
-    'Wakes' : list of str, # LIST of names of physical group containing the wake
-    'WakeTips' : list of str, # LIST of names of physical group containing the edge of the wake (not for 2.5D)
-    'TeTips' : list of str, # LIST of names of physical group containing the edge of the wake and the trailing edge
-    # ... optional for 3D
-    'Symmetry' : str, # name of physical group containing the symmetry boundaries
-    # Freestream
-    'M_inf' : float, # freestream Mach number
-    'AoA' : float, # freestream angle of attack [deg] (optional, default=0)
-    'AoS' : float, # freestream angle of sideslip [deg] (optional, default=0)
-    'Q_inf' : float, # freesteam dynamic pressure (only required for aerostructural computations)
-    # Geometry
-    'S_ref' : float, # reference surface length
-    'c_ref' : float, # reference chord length
-    'x_ref' : float, # x-coordinate of reference point for moment computation
-    'y_ref' : float, # y-coordinate of reference point for moment computation
-    'z_ref' : float, # z-coordinate of reference point for moment computation
-    # Numerical
-    'LSolver' : 'GMRES', # inner solver (PARDISO, MUMPS or GMRES)
-    'G_fill' : int, # fill-in factor for GMRES preconditioner (optional, default=2)
-    'G_tol' : float, # tolerance for GMRES (optional, default=1e-5)
-    'G_restart' : int, # restart for GMRES (optional, default=50)
-    'Rel_tol' : float, # relative tolerance on solver residual
-    'Abs_tol' : float, # absolute tolerance on solver residual
-    'Max_it' : int # maximum number of iterations for nonlinear solver
-    }
-```
 *Note* DART can be coupled with [pyGeo](https://github.com/mdolab/pyGeo), which uses the free-form deformation technique, to perform aerodynamic shape optimization. Since pyGeo only handles 3D geometries, users wanting to perform 2D shape optimization must provide a so-called 2.5D geometry, which consists of an extruded 2D geometry enclosed between two symmetry walls. In such a case, the parameters `'WakeTips'` MUST NOT be given.
 
 **2. Using the interface**  
-Once the parameters have been defined, the interface can simply be setup by calling,
-```python
-dart = DartBuilder(p, scenario=..., task=...)
-```
-where valid choices for `scenario` are `'aerodynamic'` or `'aerostructural'`, and valid choices for `task` are `'analysis'` or `'optimization'`.  
-Users must then refer to the MPHYS documention to connect the interface through MPHYS. In version 0.4.0, this is done by calling,
+Users should refer to the MPHYS documention to connect the interface through MPHYS. In version 0.4.0, this is done by calling,
 ```python
 # for pure aerodynamic computations...
 from mphys.scenario_aerodynamic import ScenarioAerodynamic