“…The expectation values of physical properties are evaluated using the corner transfer matrix renormalization group (CTMRG) [24,32] with the environment bond dimension χ = D 2 . The results can in principle be improved with increasing D, but the computational cost explodes as D 12 . Fortunately, we find D = 12, which is the limit of our numerical capability, can already give some con-vergent results for the present model.…”