I guess that you mean the solutions to the problems given in the book "Solid State Physics" by Ashcroft and Mermin. I doubt that the authors have given the solutions to their problems. The best advice I could give you would be to find a physicist specialized in solid-state physics and ask for the solutions to a few specific problems from the book.
Ashcroft-Mermin turn into "ashcraft". "Ashcraft solution" reads like "witchcraft solution"! That's what I thought at the first reading! Maryam take care of your spelling!
Just having the solution book and then not using your own brain is not a good thing. Istead, you could have tried to solve the problems yourself first and then in case you failed you could have asked questions in the research gate.
I can only just imagine the students in Tapan's classes squirming :-) I notice many dislike Tapan's straight-forwardness. Never-the-less, his advise is in the best interest of all students that are seeking betterment. Correct spellings of names is very important. Imagine me misspelling your name.
Maryam! At least to stop the negative slide in the RG score, you ought to delete/edit this post and rephrase your thoughts more cogently through study, self-help & deliberation. Good Luck!
BTW I have not even a clue regarding the subject matter. I plead total ignorance myself.