I have gone through the tutorial and the mailing list archive but I was unable to find whether it is possible to measure the correlation only between some sites of the lattice under study, say about O(n) of possible correaltions not every possible 2 sites in the lattice which is about O(n^2) and is definitely a waste of calculations in my case. So, is there any way that I can give a list (of two sites) to the program? If not, can you think of a very easy workaround?