how can I solve fsolve function error?

[deanhystad]

In the stackoverflow thread you state that the 100k curve should look a lot like the 300k curve. I don't think that is true. Lowering the temperature not only lowers the compressibility, it also changes the shape of the curve, making it much sharper. It might be that fsolve is giving up because the equation is too non-linear and you are bouncing around but not getting any closer to the solution, or it could be that there is no solution. I noticed I can make the warning go away by starting with a really small starting value for V (0.000001). The resulting curve looks like a diagonal line to me. No jaggies and no curve.