Dear all, I have defined a graphlattice which has 2 particles on each site. In other words the unit cell includes 2 vertices. But I encountered a problem using this lattice. the problems is about the correlation functions. For instance, when I want to calculate the <SzSz> correlation function( MEASURE_CORRELATIONS[Diagonal spin correlations]=Sz ) it seems that ALPS calculates the corresponding function between sites of the lattice instead of particles(vertices) on a sites. Also there is noway to calculate the correlation functons between particles on one site. I will be grateful if any one can help me. Best regards S. Raeisi ---------------------------------------------- Sadegh Raeisi Department of Physics Sharif University of Technology Quantum Information Group ----------------------------------------------