# PeriodicSpinChainJ1J2

PeriodicSpinChainJ1J2 diagonalizes the $J_1-J_2$ Hamiltonian using periodic boundary conditions. The $J_1-J_2$ Hamiltonian is defined by
$H=J_1\sum_{i=0}^{N-1} \vec{S}_{i}\cdot\vec{S}_{i+1} \; + \; J_2\sum_{i=0}^{N-1} \vec{S}_{i}\cdot\vec{S}_{i+2}$
By default, $J_1=1$ and $J_2=\frac{1}{2}$. This can be tuned using the options --j1 and --j2. Most of the options are identical to PeriodicSpinChainAKLT.