  We study the ground state phase diagram of the quantum spin-2 XXZ chain in
the presence of on-site anisotropy using a matrix-product state based infinite
system density-matrix-renormalization-group (iDMRG) algorithm. One of the
interests in this system is in connecting the highly quantum mechanical spin-1
phase diagram with the classical S=infinity phase diagram. Several of the
recent advances within DMRG make it possible to perform a detailed analysis of
the whole phase diagram. We consider different types of on-site anisotropies
which allows us to establish the validity of the following statements: One, the
spin-2 model can be tuned into a phase which is equivalent to the
"topologically nontrivial" spin-1 Haldane phase. Two, the spin-2 Haldane phase
at the isotropic Heisenberg point is adiabatically connected to the "trivial"
large-D phase, with a continuous change of the Hamiltonian parameters.
Furthermore, we study the spin-3 XXZ chain to help explain the development of
the classical phase diagram. We present details on how to use the iDMRG method
to map out the phase diagram and include an extensive discussion of the
numerical methods.
