Infinite thermal conductivity for CO2_8 mixture

[domilanza2002]

Good morning, I was trying to use the CO2_8 mixture pre-included in the data folder, but I noticed that for a little range of values, the equilibrum thermal conductivity is infinity. In particular, also the frozen thermal conductivity is infinity, so I think that the latter is the root of the problem. In the plots I attached, infinity=2 to plot it easily. I am using Python and this is the code I am running:

import mutationpp as mpp

mix = mpp.Mixture("CO2_8")

mix.equilibrate(519.0, 101325.0)

print(mix.frozenThermalConductivity())

The mixture file is:

<!-- 8-species CO2 mixture -->
<mixture name="CO2_8" state_model="EquilTP" thermo_db="RRHO" thermal_conductivity="Chapmann-Enskog_LDLT" viscosity="Chapmann-Enskog_LDLT">

    <species>
        e- C+ O+ C O CO CO2 O2
    </species>

    <element_compositions default="default">
        <composition name="default"> C:1.0, O:2.0 </composition>
    </element_compositions>

</mixture>

Thanks