  We study the entanglement Hamiltonian for fermionic hopping models on rings
and open chains and determine single-particle spectra, eigenfunctions and the
form in real space. For the chain, we find a commuting operator as for the ring
and compare with its properties in both cases. In particular, a scaling
relation between the eigenvalues is found for large systems. We also show how
the commutation property carries over to the critical transverse Ising model.
