  We study the entanglement Hamiltonian for finite intervals in infinite
quantum chains for two different free-particle systems: coupled harmonic
oscillators and fermionic hopping models with dimerization. Working in the
ground state, the entanglement Hamiltonian describes again free bosons or
fermions and is obtained from the correlation functions via high-precision
numerics for up to several hundred sites. Far away from criticality, the
dominant on-site and nearest-neighbour terms have triangular profiles that can
be understood from the analytical results for a half-infinite interval. Near
criticality, the longer-range couplings, although small, lead to a more complex
picture. A comparison between the exact spectra and entanglement entropies and
those resulting from the dominant terms in the Hamiltonian is also reported.
