Dear alps::SimpleObservableEvaluator,

Look at the Hubbard model definition. It defines two constraints Nup_total and Ndown_total that you can set after defining Nip and Ndown as conserved quantum number.

Matthias

On 12 Jan 2010, at 09:33, Mykola Maksymenko wrote:

Dear all,

I perform a full diagonalization of Hubbard hamiltonian using a fulldiag application. I'm interested in energy spectrum for low densities of electrons only, or even fixed number of electrons on the lattice. So I don't really need to go over all subspaces with number of electrons N=0..N_total.

I would be tankful for a hint where and how can I modify the code to fix the N? :)

Best regards,

Mykola