The QMC codes do not support fermionic models for the simple reason that because of the negative sign problem these algorithms are not really useful anyway. Matthias On 20 Oct 2007, at 12:28, Aniket Kulkarni wrote:

Dear all, I am new user to alps. I want to calculate magnetic susceptibility for the square model(4 * 4) using Hamiltonian fermion Hubbard. For this I am using looper and dirloop_sse algorithm. But it is not running at all. It is showing following error Cannot convert fermionic operator to a bosonic matrix

So please tell me how to calculate?

Thanks in advance

with regards, Aniket