Contains the basics of the symmetric groupPresents the four different methods for the construction of spin eigenfunctionsCovers both the unitary group and symmetric group approachesThe spin-coupled valence bond method-presented for the first time in a book on this subject This is the first book to provide comprehensive treatment of the use of the symmetric group in quantum chemical structures of atoms, molecules, and solids. It begins with the conventional Slater determinant approach and proceeds to the basics of the symmetric group and the construction of spin eigenfunctions. The heart of the book is in the chapter dealing with spin-free quantum chemistry showing the great interpretation value of this method. The last three chapters include the unitary group approach, the symmetric group approach, and the spin-coupled valence bond method. An extensive bibliography concludes the book.