Dear all, I am using ALPS software for exact diagonalization( Lanczos). There is much examples for writing models like Heisenberg, t-J, Hubbard etc. I have a difficulty to write a complicated Hamiltonian. For example, if I want to write "model.xml" for Hamiltonian :
H = J*nnsum(i,j)*S_{i}*S_{j} +
J'*sum(i)*sum(delx)*sum(dely)*[(S_{i}*S_{i+delx})*(S_{i+delx+dely}*S_{i+2*delx+dely})]
First term is simply Heisenberg term and second is another type coupling term. How can the second term be written in xml format. Thanking you,
With Best regards Rakesh Kumar School of Physical Sciences, JNU, New Delhi-110067 (INDIA) Mob.No.: +91-9891397108
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Dear Rakesh Kumar,
This seems to be a four-site interaction. These terms are not yet supported by ALPS, but we plan to allow them in ALPS 1.4, planned for next year.
Best regards
Matthias Troyer
On 10 Oct 2006, at 07:04, Rakesh Kumar wrote:
Dear all, I am using ALPS software for exact diagonalization ( Lanczos). There is much examples for writing models like Heisenberg, t-J, Hubbard etc. I have a difficulty to write a complicated Hamiltonian. For example, if I want to write "model.xml" for Hamiltonian :
H = J*nnsum(i,j)*S_{i}*S_{j} + J'*sum(i)*sum(delx)*sum(dely)*[(S_{i}*S_{i+delx})*(S_{i+delx+dely}*S_{i+2*delx+dely})]
First term is simply Heisenberg term and second is another type coupling term. How can the second term be written in xml format. Thanking you,
With Best regards Rakesh Kumar School of Physical Sciences, JNU, New Delhi-110067 (INDIA) Mob.No.: +91-9891397108
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