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The spin-1/2 XXZ Heisenberg chain with two types of boundary terms isconsidered. For the first type, the Hamiltonian is hermitian but not for thesecond type which includes the U_{q}[SU(2)] symmetric case. It is shown thatfor a certain `tuning' between the anisotropy angle and the boundary terms thespectra present unexpected degeneracies. These degeneracies are related to thestructure of the irreducible representations of the Virasoro algebras for c<1.Comment: 9 pages; an old preprint from the pre-arXiv (but not pre-LaTeX) era,  published version not (yet?) electronically accessibl

THE MODIFIED XXZ HEISENBERG CHAIN: CONFORMAL INVARIANCE, SURFACE EXPONENTS OF c<1 SYSTEMS AND HIDDEN SYMMETRIES OF FINITE CHAINS