Density matrix renormalisation group study of the correlation function   of the bilinear-biquadratic spin-1 chain
  Using the recently developed density matrix renormalization group approach, we study the correlation function of the spin-1 chain with quadratic and biquadratic interactions. This allows us to define and calculate the periodicity of the ground state which differs markedly from that in the classical analogue. Combining our results with other studies, we predict three phases in the region where the quadratic and biquadratic terms are both positive. 
R. J. Bursill, T. Xiang, G. A. Gehring