LAUSR

Using the fermionic basis, we obtain the expectation values of all $${\mathfrak {sl}}_{2}$$sl2-invariant and C-invariant local operators on 10 sites for the anisotropic six-vertex model on a cylinder with generic Matsubara data. This is equivalent to the generalised Gibbs ensemble for the XXX spin chain. In the case when the $${\mathfrak {sl}}_{2}$$sl2 and C symmetries are not broken this computation is equivalent to finding the entire density matrix up to 10 sites. As application, we compute the entanglement entropy without and with temperature, and compare the results with CFT predictions.