ALPS users and developers,<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; I have two questions about the definitions of lattice sizes and the initial states for mps_optim.<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 1, how to create a infinite size of lattice? And how to define filling of the lattice for DMRG or MPS?<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 2, if the lattice size is finite and is very large, how to quickly set the quantumnumbers of the initial state for all sites?<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Thanks. <br><br>Xiao Liang<br>