CEA Equilibrium Chemistry - Matlab interface

[jmm1234567]

Hello,

I am looking to run equilibrium chemistry analysis via the Matlab interface that has been developed. I've been running CEA for some time and readily ran the FORTRAN version in the past. The problem I'd like to solve is a high temperature equilibrium one with ionization. Previously I would simply set up an *.inp file that would look somthing like this for a synthetic air simulation:

problem    ions 
      tp   t,k=10000,9000,8000,7000,6000,5000,4000,3500,3000,2500,2000,1500,1000,500,  p,mmhg=100,200,300,400
react  
  name=N2 moles=.8  t,k=300
  name=O2 moles=.2  
only 
  e- N N+ N- NO NO+ NO2 NO2- NO3 NO3- N2 N2+ N2- N2O N2O+ N2O3 N2O4 N2O5 
  N3 O O+ O- O2 O2+ O2- O3 
output  
    plot p t rho h u g s m mw cp gam son N2 O2 e- NO N O N+ O+ NO2 
end

I'm trying to emulate this input starting from the following example:

https://github.com/nasa/cea/blob/main/source/bind/matlab/samples/equilibrium_example.m

My solver inputs look like:

solution = ceam.eq_solve(cea.TP, reac_names, T=T_eq, P=P_bar, ...
        fuel_amounts=py.numpy.array(fuel_moles), ...
        oxid_amounts=py.numpy.array(oxidant_moles), ...
        moles=true, ...
        only=prod_names);

It's working and can easily be looped to develop plots over a prescribed temperaure range but there are a few things I'd like to add and streamline:

1. How can I switch on ions/e- in the 'ceam.eq_solve' call?
2. I would like to avoid using "fuel_amounts" and "oxid_amounts" and simply use "reac_amounts" or the like if possible. Is there a way to do so with my desired 0.8 moles/0.2 moles N2/O2 synthetic air mix as I showed in the simple equilibrium chemistry *.inp text above?
3. Is there any prefered citation if we use this work for any papers/talks?

Many thanks!

[jmm1234567]

I found a hint on how to incopropoate ions/electrons via Example 11. It uses an "ions=true" statement. The solver input I tried was:

  solution = ceam.eq_solve(cea.TP, reac_names, ions = true, T=t, P=p, ...
                fuel_amounts=py.numpy.array(fuel_moles), ...
                oxid_amounts=py.numpy.array(oxidant_moles), ...
                moles=true, ...
                only=prod_names);

The only error that surfaces is one of convergence:

C:\Users\xxx\AppData\Local\Python\pythoncore-3.14-64\Lib\site-packages\cea\matlab.py:439: RuntimeWarning: EqSolver.solve: CEA_NOT_CONVERGED
  soln = _compiled_eq_solve(

Matlab subsequently freezes and needs a hard reset. I'll keep troubleshooting but any advice on the matter would be greatly appreciated.