Partial cluster expansion

Dear all,

I want to perform cluster expansion to make a convex hull for a partial range of the composition; 0 to 0.5 Al instead of 0 to 1 in Ni-Al system. In other words, Al concentration ranges from 0 to 50% (at%) in Ni-Al system. Is it possible by cluster expansion code?

Thank you.

Warm Regards,
Shailendra