  In this note, first the Recurrent Variational Approach (RVA) is introduced by
using as example a non-trivial spin-model, the spin-1/2 antiferromagnetic
two-leg-ladder. Then, a first application of this scheme to the electronic
structure of conjugated polymers is proposed. An analogy between the two-leg
ladder and the dimerized chain described by the Extended Peierls-Hubbard
Hamiltonian is underlined and comparisons are made with DMRG calculations. The
proposed ansatz is useful to get some analytical insight and it is a good
starting point for further improvements using the RVA.
