Error in mixture calculation for nitrogen and hydrogen

[Nikolaj Maack Bielefeld]

Hi group

We are calling CoolProp from matlab. It works fine for fine for pure species.

When calling CoolProp for a 50/50 mixture of nitrogen and hydrogen at ambient conditions, we get the error message below. Does anybody know what it means and if there is an easy solution? We thought about maybe applying a simple linear mixing rule (as specified on the webpage) instead if there is no good solution to this problem. :-) I also have REFPROP that I can use for validation, but my group does not have access to it. That is why we use CoolProp.

Error using CoolProp/CoolProp.__Props_err2 (line 344)
Python Error: ValueError: One stationary point (not good) for T=300,p=100000,z=[ 0.612767201791, 0.387232798209 ] : PropsSI("Hmolar","T",300,"P",100000,"Hydrogen[0.5]&Nitrogen[0.5]")

Error in CoolProp/CoolProp.PropsSI (line 457)

Error in CoolProp/CoolProp.PropsSI (line 377)