My tutor asked us today to consider the partition function of the following model as an aside to our topic at the moment. I went to work out the maths of it today and I'm quite stuck for how the calculation can proceed. It's a 1d closed chain with some number, n, points. Each point has some value of spin associated with it, with the possible values ranging from -s to s in steps of 1. With H=gμB*(the sum over all of the possible spin configurations) where mu is the bohr magneton.