Spin-adapted Matrix Product States and Operators

Abstract: Matrix product states (MPSs) and matrix product operators (MPOs) allow an alternative formulation of the density matrix renormalization group algorithm introduced by White. Here, we describe how non-abelian spin symmetry can be exploited in MPSs and MPOs by virtue of the Wigner--Eckart theorem at the example of the spin-adapted quantum chemical Hamiltonian operator.