Örs Legeza - Wigner Research Centre for Physics In this contribution, we overview tensor network states techniques that can be used for the treatment of high-dimensional optimization tasks used in many-body quantum physics with long range interactions and ab initio quantum chemistry. We will discuss the controlled manipulation of entanglement in light of fermionic orbital optimization. Recent developments on tree-tensor network states, multipartite entanglement, time-dependent variational principle (TDVP), externally corrected coupled cluster density matrix renormalization group (DMRG-TCCSD) method, will be discussed in more detail. Finally, some new results will be shown for extended periodic systems in one- and two dimensions, for topologically protected end spins in carbon nanotubes, for transition metal complexes, graphene nanoribbons and Wigner crystals.