Dear teacher!

  I am interested in the magnetic simulation by using SSE package. I have a system of the cluster, including six cobalt. The hamiltonian is as follow:

H=-2{J1*[ S1*S2 + S4*S5 ] + J2*[ S2*S3 + S6*S5 ] + J3*[ S3*S4 + S1*S6 ]}

  How do I write the model?

  I have read the model.xml file in the ALPS software. But the example is almost infinite system, but not isolate system in the file.

  Please help me!