I would like to use ALPS to study a spin model defined on an open chain in which one or two sites in the middle of the chain can host "defects", for istance the local magnetic field and/or the exchange with neighbouring sites are different from all the other interactions in the chains.
Can it be done by proper definitions in the lattice.xml file? (and of course then also in models.xml)
Thanks a lot for your work. Cheers, Cristian