SAFT gamma mie : computing density of benzene

[Govnavid]

Hello Gustavo.
I just ran the creating components and mixtures example for saft gamma mie provide in the documentation. It ran fine when I calculating the density of water. However there was a ValueError for benzene. Here is my calculation code:

creating component

benzene = component(GC={'aCH':6})
benzene.saftgammamie()
eos = saftgammamie(benzene)

density for liquid phase

T = 373. # K
P = 1e5 # Pa
rhol = eos.density(T, P, 'L')
print(rhol)

According to the example, I need to create a dictionary using the group's names as keys and the numbers of times this group is present as values. But according to my code above, the program cannot proceed. I can't find a solution. Can you give me an example of computing density of benzene.

Thank you very much.
Best whises!

[gustavochm]

Hi Govnavid,

Thanks for using sgtpy! Can you provide more information on what error are you getting? I just run the same script that you wrote and sgtpy is finding the volume root (see the attached figure)

Regards,
Gustavo

[Govnavid]

Hello Gustavo.
My code is exactly the same as yours, but there is a problem in the figure below. The sgtpy version I installed is the latest version 0.015.
I still don't have a solution. Could you please give me some advice?

Best Regards,
Govnavid.

[Govnavid]

Hello Gustavo.
Here is my complete code.

Best whises,
Govnavid.

[gustavochm]

Ohh now I see what happened. This was a bug for molecules that had association sites but that wasn't self-associating. I fixed the bug on the GitHub repo but apparently, I forgot to upload the updated to PyPI.
I'm going to upload the updated version to PyPI now, however at this moment I only have access to a mac computer, so I won't be able to upload precompiled windows versions. If you are using windows, you will need a C compiler.

If you are using windows and don't have a C compiler, a workaround would be to modify the config_asso.py file (located at C:\Users\SunShow\AppData\Roaming\Python\Python39\site-packages\sgtpy\config_asso.py). You need to modify lines 246 to 250 to the following:

indexABij1 = np.hstack([indexABij1])
indexABij2 = np.hstack([indexABij2])

indexAB_id1 = np.hstack([indexAB_id1])
indexAB_id2 = np.hstack([indexAB_id2])

Hope that helps,
Gustavo!

[Govnavid]

Thank you very much for you answer.
I'll solve the problem in your way. If possible, I hope you can upload the update version to PyPl later. Thanks again for your kind help.
Best whises!