The search for the is a rite of passage for condensed matter students. It usually ends in frustration or a malware warning. The hard-earned lesson is that solid state physics is not a subject meant to be "checked" in the back of a book; it is meant to be wrestled with.
If you are looking for help with the 100+ problems found in the 4th Edition , here is where students typically find resources: Harald ibach hans l th solid state physics - Studypool Solid State Physics Ibach Luth Solution Manual
If you have found a solution manual or a set of worked problems, the temptation is to "reverse-engineer" the answer. However, to truly master the material, consider this approach: The search for the is a rite of