Dear ALPS community, We are interested in studying a generalized classical XY model containing both cos(theta_i-theta_j) and cos(2(theta_i-theta_j)) terms. I have a couple of questions: 1. Is it possible to do classical worm simulations using (perhaps a simple modification of) the QMC worm code? 2. If so, can a term like cos(2(theta_i-theta_j)) be specified in the quantum mode, where it corresponds to pair hoppng? Many thanks, Austen Lamacraft