Fortran code for spins in heisenberg hamiltonian

• Fortran
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?

Mark44
Mentor
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?