Dear Matthias, I attach to this mail the lattice and model files I am trying to use. test.py is then the python file which uses them.
Many thanks again. Regards.
On 27 November 2012 12:47, Matthias Troyer troyer@phys.ethz.ch wrote:
Hi,
can you send your complete set of input files as otherwise it is hard to help.
Matthias
On Nov 27, 2012, at 7:38 AM, Emanuele Levi emanuele.levi@gmail.com wrote:
Dear ALPS developers, Thank you for your quick and very helpful reply. I might be doing something wrong as is the first time I define a lattice in ALPS by myself. I want to add to the Heisenberg Hamiltonian on a 1d spin chain the term
Sz(i)*Sz(i+2)
In the lattice file I set the basis as
<BASIS><VECTOR>1</VECTOR></BASIS>
and in the unit cell I put the two bonds
<EDGE type="0"><SOURCE vertex="1" offset="0"/><TARGET vertex="1" offset="1"/></EDGE> <EDGE type="1"><SOURCE vertex="1" offset="0"/><TARGET vertex="1" offset="2"/></EDGE>
which, as far I have understood connect respectively sites 1, and 2 lattice spacing far. Then in the model file I define the bond operators as
<BONDOPERATOR type="0" name="usual" source="x" target="y"> usual Heisenberg bond term... </BONDOPERATOR> <BONDOPERATOR type="1" name="test" source="x" target="y"> Sz(x)*Sz(y) </BONDOPERATOR>
and I put them in the Hamiltonian as
<BONDTERM type="0" source="i" target="j"> usual(i,j) </BONDTERM> <BONDTERM type="1" source="i" target="j"> Jtest*test(i,j) </BONDTERM>
But it gives me error. It creates the parameter file but doesn't manage to compute any simulations (fulldiag, dmrg, etc etc). I think is the way I have written it that has something wrong. Moreover I don't manage to use printgraph in any way to see if the lattice is correct. Do I have to use printgraph on the xml lattice file?
Many thanks in advance for your help. Kindest regards.
-- Emanuele Levi
emanuele.levi@gmail.com