Hi,

On 24 May 2016, at 05:00, 梁霄 lxxhlb@mail.ustc.edu.cn wrote:

ALPS users and developers, I have two questions about the definitions of lattice sizes and the initial states for mps_optim. 1, how to create a infinite size of lattice? And how to define filling of the lattice for DMRG or MPS?

DMRG is only a finite size method. You can set the conserved quantum numbers by defining something like CONSERVED_QUANTUMNUMBERS=“N" N_total = 10 More here: http://alps.comp-phys.org/static/mps_doc/parameters.html

  2, if the lattice size is finite and is very large, how to quickly set the quantumnumbers of the initial state for all sites?

If you are using the above parameters, a default initial state will be created with the desired quantum numbers. If you are creating a custom initial state with the “initial_local_QN” parameter, I suggest to generate the input files from a scripting language, for example Python.

Best, Michele