Initial guess length mismatch when eps_a is of type list

[Andrew-S-Rosen]

When running run_model.py, I get the following traceback. It seems to be that the initial guess list has length 5, but when this is unpacked in CatChemi, it's expecting a length of 3. Changing EPS_A_VALUES to a List[float] rather than List[List[float]] resolves the issue, so it's just related to when one wants to use multiple values for eps_a for a given adsorbate.

Fitting parameters for adsorbate ['CO'] with eps_a [[-7, 2.5]]
Fitting parameters for adsorbate CO with eps_a [-7, 2.5]
Initial guess:  [0.01, 0.01, 1.8849555921538759, 1.8849555921538759, 0.1, 0.1]
Traceback (most recent call last):
  File "run_model.py", line 176, in <module>
    fitting_odr = odr.ODR(data, fitting_model, initial_guess)
  File "/home/arosen/anaconda3/envs/na/lib/python3.8/site-packages/scipy/odr/_odrpack.py", line 784, in __init__
    self._check()
  File "/home/arosen/anaconda3/envs/na/lib/python3.8/site-packages/scipy/odr/_odrpack.py", line 845, in _check
    res = self.model.fcn(*arglist)
  File "/home/arosen/anaconda3/envs/na/lib/python3.8/site-packages/catchemi/NewnsAndersonRepulsion.py", line 72, in fit_parameters
    alpha, beta, constant_offset = args
ValueError: too many values to unpack (expected 3)

[sudarshanv01]

Hi @arosen93 ! My guess is that the error comes from the fact that I updated CatChemi over the weekend sometime with the commits that allow running adsorbates like CO, with two different $\epsilon_a$ values. If you pulled the latest version of CatChemi does it work?

For reference here are the CO parameters I get:

{"alpha": [2.1901565682765116, 0.030158212016204583], "beta": [0.10287271431680009, 8.475571101032806], "delta0": 0.1, "constant_offset": [2.8384770534608363, 2.7340421739193794], "eps_a": [-7, 2.5]

[Andrew-S-Rosen]

Hi @sudarshanv01! Odd! Yup, I just tried again and git clone'd the current main branch of CatChemi but still get the ValueError: too many values to unpack. This is with just doing python run_model.py for clarity. If it seems like this shouldn't be happening in the main branch, we can chat in person about it too.