1. The problem statement, all variables and given/known data Determine the energy levels, their degeneracy and wave functions (in ket notation) of a particle with spin quantum number s =1 if the Hamiltonian is [itex]AS_x^2 + AS_y^2 + B S_z^2[/itex] where A and B are constants. 3. The attempt at a solution' I've spent ages thinking about this but I keep finding that the Hamiltonian is [itex](\hbar^2/4)(2A + B)I[/itex] where I is the identity matrix. This is very strange since it implies that there are an infinite number of eigenstates with identically the same eigenvalue!