1. The problem statement, all variables and given/known data Some atoms in Cu crystal (Cu has a FCC lattice) are replaced by Zn atoms. Taking into account that Zn is bivalent, while Cu is monovalent, calculate the atomic ratio of Zn to Cu in ZnCu alloy at which the Fermi surface touches the first Brillouin zone faces. Use the free-electron model and assume that lattice constant does not change with Zn doping. 2. Relevant equations N/A 3. The attempt at a solution I would like some help getting started on this problem. Any help is much appreciated thank you very much!