Fortran code for spins in heisenberg hamiltonian

[quin]

hi friends. i dont know how can i write a fortran code for expressing spins in heisenberg model which have 3 dimension spin operator, sx,sy,sz?
thanks for your help

 

[Mark44]

hi friends. i dont know how can i write a fortran code for expressing spins in heisenberg model which have 3 dimension spin operator, sx,sy,sz?
thanks for your help

What have you tried? We are not going to write the code for you, if that's what you had in mind.